Anti Techeiles – Bigdei Chamudos – Rabbi Doniel Osher Kleinman

B’ezras Hashem, the night of 9 Tammuz 5777

Kavod Yedidi, HaRav HaGaon, etc., Shlita,

I received your esteemed letter regarding the Murex trunculus snail, which some argue is the Chilazon of Techeiles. Though my time is limited, and there is much work to be done, due to the importance of the matter, I will try to respond as best as I can, and let us see what emerges.

You wrote to reconcile the Murex with what Chazal say in Menachos 44a—that “this Chilazon, its body resembles the sea, and its form resembles a fish”—explaining that even though it’s not the most straightforward understanding, it still works. You propose that in the time of Chazal, the Techeiles industry was well-known, with a strong presence, and everyone knew that the primary location of the Chilazon was around Eretz Yisrael and Bavel, from Sulamos Tzur to Haifa. People also understood the term Chilazon as referring to certain worm- or slug-like creatures of a specific form. The main point of Chazal, you suggest, was to give identifying signs to distinguish among the various shellfish found along that stretch of coastline: some had a greenish covering that made them resemble the sea, though they didn’t look like fish; others resembled neither the sea nor a fish; and perhaps some resembled fish but not the sea. The two most striking features of the Chilazon, when found in the sea, were the greenish appearance of its shell and its overall shape—broad in the middle and tapered at the edges. You argue that, technically, Chazal could have just said: “This Chilazon has a greenish look on its body, and its shell is broad in the middle and tapered at the edges.” But instead, they used a more concise expression that would have been well understood by those familiar with these creatures—“it resembles the sea, and it resembles a fish.” That is your reasoning.

However, I still struggle to understand your explanation that “resembles the sea” means it resembles the seabed because it is covered in a biological layer that is greenish or brownish. The Gemara earlier (43b) states: “Techeiles resembles the sea,” which, according to most Rishonim, clearly refers to the blue color of the sea. (One must analyze Rashi in Berachos 9b and his commentary on the end of Parshas Shelach, where he says it is green.) Either way, those who support the Murex interpret the word yam in that Gemara as referring to a blue color. According to your approach, however, the word yam is being used in two different ways in the span of just a few lines of the Gemara: first to mean the color of the sea (i.e., blue), and then immediately afterward to mean the seabed (i.e., green or brown). Granted, different Tannaim or Amoraim may have said each statement, but it is still astonishing that none of the Rishonim ever felt the need to explain this difference. This is difficult to accept.

Furthermore, the phrase “its appearance is like the sea” appears in the Rambam (Hilchos Tzitzis 2:1), in the Sefer HaChinuch (mitzvah 386), and in the Sefer Mitzvos Gadol (Asei 26). According to your position, those who lived in the time of Chazal would have immediately understood that this description referred to the phenomenon they were familiar with. But by the time of the Rishonim—when the Chilazon was already no longer found—wouldn’t it have been necessary for them to clarify the intended color, since yam does not obviously mean green? Indeed, the Maharil (Teshuvos Siman 18) writes that based on the simanim given by the Semag, it should have been easy to find the Chilazon. However, according to your explanation, it would remain an unsolved mystery, only understandable to those familiar with the dyeing process of these shellfish.

And it becomes even more difficult based on the wording of the Sefer Mitzvos Gadol (Semag), who writes: “It is a fish whose eye resembles the color of the sea, and it secretes a dye that resembles the sea.” Are we to say that even here the word yam has two different meanings? This is why I cannot accept this explanation of the Gemara. Certainly, it cannot be the meaning of the Semag and the Rishonim. Since the Rishonim wrote in a concise manner without elaborating, it is clear that they held yam means its simple and obvious meaning—so that must be the explanation of the Gemara as well. We have no justification to deviate from the words of the Rishonim, even slightly.

Furthermore, the Beraisa in Maseches Tzitzis states that “its body resembles the sky,” which proves that when the Beraisa in Menachos says “its body resembles the sea,” it means the color of the sea’s waters—because certainly, we do not want to set up contradictions between the Beraisos when they can be reconciled simply. My dear friend HaRav HaGaon R’ Y.B., shlit”a, proposed that the Beraisa in Maseches Tzitzis is unreliable and contains errors. But in my humble opinion, one should not amend texts without solid proof, especially in this case, where the simplest understanding is that “resembles the sea” and “resembles the sky” are one and the same. The proof he brought from the textual variant “it rises once every seven years”—suggesting that it was originally seventy years—makes sense, as it is a small scribal error, but to change yam to rakia (sea to sky) is something else entirely. We must accept the wording of the Tosefta as it is, unless there is a strong reason to change it. Even then, we should be extremely cautious, as seen from the Ramban in Bava Metzia 23b and 43b (see his discussion on textual accuracy).

Now, according to what you wrote—that the identifying signs given in the Gemara were describing a phenomenon well-known to them, since they had a thriving dye industry that relied on these shellfish, and Chazal were speaking to those who saw large numbers of these creatures regularly—then logically, the sign of “it rises once every seventy years” should also be something that was observable in their time. It is unreasonable to say that Chazal would mention an identifying sign that had no practical relevance to them, since that would lead to confusion when encountering a Chilazon that matched the other criteria but did not have this particular trait. Based on this, you seem to be assuming that the Chilazon still did emerge only once in seventy years at that time. But this raises a strong question—why do we not find this characteristic in any mention of the Murex Trunculus? Nowhere in the writings of the ancient nations—upon which all Murex proponents rely—do we find any mention of such a phenomenon.

In my humble opinion, the identifying signs listed in the Gemara were not necessarily based on phenomena visible in their own time. Rather, the Chilazon of Techeiles was already hidden away by the time this Beraisa was recorded. This fits with the Sifri on Parshas V’Zos HaBeracha and the Midrash of the Arizal, cited in various seforim, which state that Techeiles is tied to the existence of the Beis HaMikdash. It is also well known that many great Acharonim—such as the Yeshuos Malko (Siman 1-2) and R’ Yosef Palagi in his glosses on Ayin HaTecheiles—hold that we do not reinterpret Midrashim allegorically; they should be taken at face value. Likewise, Rav Chaim Kanievsky, shlit”a, wrote explicitly that Techeiles was hidden away. In my view, this is also the intention of the Gra in Orach Chaim 9:2, where the Mechaber writes “Nowadays, we do not have Techeiles.” The Gra comments: “See Midrash Rabbah, Parshas Shelach (end of 17): and now we have only white strings.” This is puzzling—why would the Gra need a Midrash to prove what was already an obvious historical fact, that Techeiles was unavailable in his time? It must be that the Gra understood that the Mechaber meant it in an absolute sense—that Techeiles no longer exists in our time. This implies that he held that the Chilazon was literally hidden away, contrary to the Maharil (Siman 5). For years, I have not found any other way to interpret the Gra’s words.

At any rate, in my humble opinion, the Chilazon of Techeiles was already hidden away in the days of Rav Chiya and Rav—the very beginning of the Amoraic period. As for the proof some bring from the story of Rav Achai in Menachos 43b and the case of Rava in Sanhedrin 12a, I find it difficult to understand. In the Gemara in Menachos, it says that Mar Yannuka and Mar Kashisha brought Techeiles threads, not Chilazon blood! Presumably, they had found wool dyed with Techeiles and wanted to clarify whether it was authentic or just Kala Ilan (indigo). Similarly, in Rava’s case, the Gemara says only that they brought him Techeiles, meaning dyed wool, not Chilazon blood.

Based on this, the identifying signs given in the Gemara were not describing a phenomenon that was still observable at the time—it was just a tradition about the nature of the Chilazon in the past. This would include the sign of “it rises once every seventy years”—not as something seen in their time, but rather as part of the Mesorah about how the Chilazon behaved when it still existed. This, I believe, is why the Rambam (Hilchos Tzitzis 2:1) does not record this as one of the identifying signs—because by his time, this characteristic was no longer relevant, as the Chilazon was already hidden. This might also be what the Radbaz (Teshuvos 2:685) intended, though it is not absolutely clear.

From this perspective, it makes perfect sense why the writings of the ancient nations do not mention this phenomenon—because by their time, it was no longer around. But according to what you wrote—that Chazal were describing something observable in their time—it follows that the sign of “it rises once every seventy years” must also have been something observable then. If so, it is astonishing that we do not find any record of this trait in any of the ancient sources on the Murex. That itself is a strong indication that the Murex Trunculus is not the Chilazon of Techeiles.

In Rashi on Shabbos 74b, he writes that the Chilazon is “like a small fish.” He does not say outright that it is a fish, but rather that it resembles a fish. In my view, it is clear that he is following the wording of the Gemara in Menachos 44a, which states “its form resembles a fish.” Meaning, its shape is similar to that of a fish—i.e., it has fins or some other structural feature that gives it a fish-like form. This aligns well with what Rashi in Sanhedrin 91a writes, that the Chilazon is a tolaas (a worm). There do exist sea creatures that are both worm-like and fish-like, such as sea slugs, which indeed have a worm-like body but also resemble small fish in certain ways. However, based on what you wrote—that the Chilazon is a snail or a lizard-like creature (chomet)—this does not fit with Rashi’s phrase “like a small fish,” and it is even more difficult to reconcile with his term tolaas (worm).

Additionally, Rashi at the end of Parshas Eikev quotes a Midrash that refers to a chomet (a skink-like reptile), saying: “Its shell grows with it.” The Midrash itself uses the phrase Chilazon, but Rashi avoids using that term in this case, which implies that he does not equate the Chilazon of Techeiles with a chomet. Likewise, in Avodah Zarah 28b, Rashi explains that the Chilazon is Limtza—which is a type of chomet—but in discussing the Chilazon of Techeiles, he avoids this term.

As for the citation from the Eglei Tal (Meleches Dash, Siman 7, Sif-Katan 26)—I am unsure what the intended proof is. In fact, in Eglei Tal (Sif-Katan 25), he brings an alternative interpretation from a certain scholar who suggested that the Chilazon grows inside a shell, and that p’tzi’a (crushing) means extracting it from the shell. But the Eglei Tal himself rejects this view. Nowhere does he say that Rashi holds this opinion. On the contrary, his words imply that, according to Rashi and Tosafos, the Chilazon grows without a shell. Additionally, in Eglei Tal (Meleches Dash, Siman 15, Sif-Katan 5), he questions why Rashi interprets p’tzi’a as pressing the body rather than cutting it with a knife (since elsewhere p’tzi’a means cutting or splitting). Nowhere in the Eglei Tal do I see a basis for claiming that the Chilazon has a shell.

From all this, the plain meaning of Rashi is that the Chilazon is a worm-like creature, not a chomet (lizard) or a snail. The same is true of other Rishonim who describe it as a tolaas—they clearly mean something more like a worm than a snail or reptile. My esteemed friend, HaRav HaGaon R’ Y.B., suggested that the Raavya, R’ Shimshon, and the Raavad only described it as a worm because of the specific context in which they were writing, but I find this argument weak. If they had meant a snail or chomet, they could have simply written that explicitly. There is almost no precedent for calling a chomet a tolaas, since tolaas refers to worms, while chomet refers to skink-like reptiles or gastropods.

I also find it surprising that my esteemed friend wrote: “How can we presume that Rashi rejected the porphyra (Murex) simply because he called it a worm?”—as if this is some novel question. On the contrary, the real novelty is to suggest that the words tolaas (worm) and k’min dag katan (like a small fish) somehow include snails or chomet-type creatures! If there were a contradiction—if Rashi explicitly called it a chomet elsewhere—then we would be forced to reinterpret his words. But in the absence of such a contradiction, why should we force ourselves into such an unnatural reading?

I’ve already proven from Tosafos and Toharas HaBayis on Shabbos 75a that the Chilazon dies immediately when taken out of the water. This was obvious to them, to the point that they questioned whether one would be liable for Netilas Neshamah (taking a life) when removing it, just like with a fish that dries to the size of a sela. They resolved that perhaps the Chilazon convulses in a way that accelerates its own death, so the one capturing it is not considered to have killed it directly. Clearly, they held the Chilazon was a type of fish.

Now, if the Chilazon is the Murex Trunculus, we end up with contradictions among the Rishonim. According to Rashi, it’s a chomet (lizard-like creature); according to Tosafos and the Rosh, it’s a fish. We also get a major dispute between Rabbeinu Tam and the Rosh versus the Ritva, Ramban, Ra’ah, Me’iri, and Chidushei HaRan about whether Dam Chilazon is just a secretion stored separately (Mifkad P’kid) or actual blood (Chiburei Michbar).

But with my explanation, there’s no contradiction between the Rishonim. Even Rashi saying it’s “like a small fish” (Shabbos 74b) fits—he means it’s a sea worm that looks like a fish (i.e., a sea slug). This also fits the Rambam, Semag, Sefer HaChinuch, and Midrash HaGadol, who call it a fish—not that it’s literally a fish, but that it’s a sea creature shaped like one.

Likewise, even Ritva, Ramban, Ra’ah, and Chidushei HaRan, who describe the Chilazon as an opaque-bodied sea creature, could be referring to such a worm. Nowhere do we find any source in Shas or Rishonim saying the Chilazon is a chomet (lizard-like creature). On the contrary, Rashi and others call it a tolaas (worm), which contradicts the idea that it’s a snail or a lizard.

Anyone who studies the sugya objectively—without forcing modern theories—would see this clearly. As for the dispute between Rabbeinu Tam and the Ritva—whether the Dam Chilazon is a stored secretion (Mifkad P’kid) or real blood (Chiburei Michbar)—I’ve already proven that according to the Ritva, the Murex cannot be the Chilazon.

Murex proponents argue that their theory fits Rabbeinu Tam, but even that is questionable:

1. Even Rabbeinu Tam’s Tosafos calls the Chilazon a fish, not a lizard.
2. Rabbeinu Tam still holds that the dye is actual blood, just categorized differently.

This is clear from Midrash Tanchuma (Terumah 5): “Techeiles is dyed in blood, as a remembrance of the sign that our forefathers established.” This means it’s actual blood, not a secretion stored in a separate sac.

Beyond that, the Murex theory forces an unreasonable conclusion: that the Rishonim argued over physical reality itself—as if some held the Chilazon had real blood while others thought it had only a secretion. But such disputes about facts are extremely rare in halacha. More likely, they argued about how to categorize the blood, not its existence.

The Chasam Sofer (Kesubos 5a) makes this point about Dam Besulim (hymenal blood): The Amoraim don’t argue about its reality, just whether it’s considered Mifkad P’kid or Chiburei Michbar. He even suggests that according to Rabbeinu Tam, Dam Chilazon is still more integrated than Dam Besulim! If so, the Murex—whose dye is a chemical secretion, not real blood—does not fit either Rabbeinu Tam or the Ritva.

So my approach avoids contradictions and keeps all the Rishonim aligned. But Murex proponents must claim:

• Rashi and Tosafos argued about what the Chilazon was.
• Rabbeinu Tam and the Ritva argued about its physical nature.
• Rambam, Semag, and Sefer HaChinuch contradicted Rashi on whether it was a fish, a worm, or a lizard.
• The color of Dam Chilazon was in dispute—despite all Rishonim agreeing it was actual blood.

Worst of all, Murex proponents have to claim that many Rishonim simply got the facts wrong—as if they misunderstood something central to a mitzvah they were analyzing based on mesorah and Shas.

This approach is untenable. Unless there is absolute proof from Shas, Bavli, Yerushalmi, or Rishonim, we should not force contradictions onto them. Any remaining difficulties should be left unresolved rather than reshaping the words of the Rishonim to fit modern archaeology or historical theories.

Let the academics debate in their books—but we, who follow Torah, must interpret the Rishonim through Shas and Mesorah alone.

From the words of the Rambam, Sefer Mitzvos Gadol (Semag), and Midrash HaGadol, who all wrote that its blood is black like ink, it’s clear that they didn’t hold like the Murex trunculus, because its blood isn’t black like ink. And what my esteemed friend, HaGaon Rav Y.B., shlit”a, pushed back, saying that there’s a black vein on the area where the blood is found, and that’s what the Rambam meant when he wrote that its blood is black like ink—I’m wondering if he really holds that’s the explanation of the Rambam’s words. If so, human blood should also be blue or green, since that’s the color of our veins. Why would the Rambam deviate from the simple approach and describe its blood as transparent or purple, and instead force himself to describe the blood based on the color of the vein? I’m astonished at these interpretations—why are we forcing ourselves into such an awkward position, turning everything upside down, twisting Rashi and all the Rishonim, reconciling all kinds of factual contradictions among them, and making it seem like some were mistaken in reality, chas v’shalom? And for what? Just to uphold the historical accounts that discuss this species primarily for producing the color purple rather than for producing techeiles (as is surely well known to you)? This itself undermines all their proofs from those historical sources. And even my esteemed friend, HaGaon Rav Y.B., shlit”a, was forced to stretch the words of the Rishonim, and most of the answers he gave don’t seem acceptable to me. In any case, the plain reading of the Rishonim definitely doesn’t fit with the Murex trunculus.

As for your question about why Chazal didn’t warn against using the wrong chilazon for techeiles, I don’t understand the question at all. Chazal did warn about this very clearly—by giving clear and simple simanim (as the Maharil puts it): its body resembles the sea, its form resembles a fish, and it surfaces once in seventy years. Meaning, its color is blue, its form and nature resemble a fish (meaning it has fins like a fish), and it surfaces once in seventy years. Any chilazon that doesn’t fit these simanim—meaning it isn’t blue, it doesn’t resemble a fish in form and nature, and it doesn’t surface once in seventy years—is pasul for techeiles and is classified as k’la ilan. And what my esteemed friend, HaGaon Rav Y.B., shlit”a, dismissed from my proof from the Kesef Mishneh—that k’la ilan includes all non-kosher techeiles dyes—and claimed that the Kesef Mishneh didn’t mean they’re all called k’la ilan but rather that they all have the halacha of k’la ilan, anyone who looks inside the Kesef Mishneh will see that he is explicitly discussing whether k’la ilan can serve as a general term for any techeiles dye not from the chilazon. See there.

Now, from the way you wrote at the beginning of your piece (Siman 1), it’s clear you hold that only the Murex trunculus is kosher for techeiles, not other chilonim. That itself is the foundation of your approach to the simanim mentioned in Menachos—that their main purpose was for those familiar with the many chilonim used for dyeing, so they could identify the correct one among them. If so, the same question you asked on me applies to you—why didn’t Chazal warn against other chilonim that also produce a blue color (as far as I know, at least three such species exist in the Mediterranean, and possibly more)? And your question also applies—why did they only say k’la ilan is pasul and not warn against blue dye from other chilonim, which is more durable than k’la ilan, as historical sources mention? So, you also have to conclude that the simanim themselves are Chazal’s warning. And you also have to say that blue extracted from other chilonim is included under the category of k’la ilan. So I don’t understand how one can build a proof from these questions when you anyway have to answer them in this way. And if you hold that other chilonim are also kosher for techeiles, then why were simanim even necessary? Many chilonim should be kosher even without these simanim! And I can’t accept at all the claim that the simanim are just practical guidance for hunters and dyers to make their work easier—if that were the case, why did the Rambam, Semag, and Chinuch bring down these specific simanim? If other chilonim without these simanim were also kosher, then why did they emphasize these signs? The implication of the Rambam’s words is that this chilazon specifically is required—not others.

Bottom line, even those who support the Murex trunculus also have to answer these questions in the same way. And regardless, in my opinion, there’s no real proof from them at all.

And what you elaborated about the idea that the proof comes from the combination of all the details together—if the validity of the combination depends on each individual detail being true on its own, and if some links in the chain are broken, the whole thing falls apart, then the strength of all of them together is no greater than the strength of each individual piece. And many of these details are shaky and don’t get past the level of speculation. After all, in most historical writings, it’s mentioned that this species was mainly used for producing purple, not blue. And even the archaeological finds show that it was used primarily for purple, which was the most valuable color, as is mentioned in Midrash on Parshas Naso. Even supporters of the Murex trunculus admit that most of the historical information speaks about purple dye, not blue, to the point that they have to struggle to find a few sources to prove that it was also used for blue. That’s why they bring a proof from the term ianthinus in the Roman decrees and from the fact that they found remnants of blue fabrics that contain chemicals from these mollusks. But if techeiles dyeing from these mollusks was really so widespread, it would have been clearly stated in these writings. And there are plenty of ways to explain the Roman decree and the finding of blue remnants. To be honest, after reviewing all the historical sources brought as proofs, I have serious doubts as to whether this species was actually used consistently for dyeing blue. Even before delving deeply into this sugya, things already seemed to lean towards the conclusion that it wasn’t used regularly for blue, as most of these old writings imply that it was primarily used for purple.

And regarding the argument of Murex trunculus supporters—that we don’t find much in non-Jewish writings about techeiles dyeing and that there are no significant archaeological finds from the techeiles mollusk—there’s a clear Gemara about this in Sotah 46b, where it brings the pasuk from Shoftim (1:26): And the man went to the land of the Chittites and built a city, and he called it Luz; that is its name until this day. The Gemara then says: That is Luz, where they dye techeiles. It is the same Luz that Sancheriv did not destroy, Nevuchadnezzar did not destroy, and even the Malach HaMaves has no power over it. Rather, when the elders decide their time has come, they leave the city walls and die outside. See there. Similarly, in Sanhedrin 12a, it says that Luz is the place where they dye techeiles, and the same is found in Bereishis Rabbah 89:5 and Tanna Devei Eliyahu 16, where it says: It is Luz where they dye techeiles for all of Klal Yisroel.

Now, this city has completely disappeared from human knowledge, as Rashi says in Shoftim there, and the Midrash (Bereishis Rabbah) says: The Rabbanan say, just as Luz has no mouth, so too, no person was ever able to locate the entrance to this city. Rabbi Elazar, quoting Rabbi Pinchas bar Chama, says that Luz stood at the entrance of a cave, and it was hollow, so they would enter the cave through the Luz and reach the city through the cave, etc. The Maharsha in Sotah explains that this is why Sancheriv didn’t confuse it and Nevuchadnezzar didn’t conquer it. And we find many such places in the world that have remained hidden, completely unknown, by Hashem’s design, such as the Sambatyon River and the place of the Ten Lost Tribes, who still number in the tens of thousands even in recent centuries, as mentioned in Lev HaIvri and other reliable sources. The entrance to Gan Eden and Gehinnom mentioned in Bava Basra 74a is also completely hidden. And there are many such things that remain unknown to us. So here, too, we can certainly say the same—everything remains in the state of hiddenness until Hashem reveals it to us. That’s why we don’t find anything—because, as Chazal imply, the place where techeiles was dyed was hidden. In any case, there’s no proof from existing archaeological finds that this species was mainly used for purple, and this has nothing to do with techeiles at all. I don’t understand why some people bring proofs from purple dyeing as if that proves anything about techeiles.

And there are still more questions that haven’t been answered properly in my opinion. One major question is from Menachos 42b, where the Gemara asks: Where do they dye the techeiles? Yet there’s no mention at all of exposing the dye to sunlight or boiling the wool. My esteemed friend, HaGaon Rav Y.B., shlit”a, answered that there’s a known method of dyeing blue from the Murex trunculus without sunlight and without boiling the wool. But this is very difficult, because it’s almost never mentioned anywhere, and it’s certainly not a standard method. On the contrary, from what I’ve heard, once in a while, there might be an exceptional case where the dye turns blue without sunlight or boiling, but that’s an exception, not the rule, and it happens due to various other factors.

And what he argued—that the Gemara there wasn’t trying to describe the technical details of the dyeing process—this is very hard to accept. The Gemara does bother to say that they bring dyeing ingredients and boil them in a pot—something completely obvious to anyone familiar with the dyeing trade. Why did the Gemara bother teaching us something so basic that applies to many different dyes, yet leave out the most unique factor of dyeing with the Murex trunculus? This requires serious analysis.

And the question from Shabbos 75a still hasn’t been answered—where it says that the chilazon shouldn’t die so that the dye remains strong. But for the past thirty years, all those involved in dyeing with the Murex trunculus have testified that the color doesn’t weaken at all within at least half an hour after the mollusk dies. My esteemed friend, HaGaon Rav Y.B., shlit”a, suddenly denied this metzius, even after all the experts who have worked with the Murex trunculus for the past thirty years already admitted to it. And he didn’t explain anything—he just denied it. To me, this question remains unanswered.

The question from the test that Chazal describe also still stands. The Gemara clearly states that through a test, one can distinguish between chilazon techeiles and k’la ilan. It’s obvious that in understanding a sugya in the Gemara that describes a real-world test, we should seek expert opinions from those who work in the field of dyeing to explain the nature of this test. That’s the standard approach in all cases of real-world metzius mentioned in the Gemara—when we don’t understand something, we ask experts, and only if their statements contradict Chazal do we then discuss whether to reject them.

And regarding this test, all the experts in the field of dyeing have determined that it refers to the reduction test. But this test would not help prove that k’la ilan is weaker than the dye extracted from Murex trunculus. On the contrary, because of the indigotin/indirubin present in k’la ilan, the results would actually come out the opposite! And my esteemed friend, HaGaon Rav Y.B., shlit”a, didn’t respond to this at all. He only said two things:

1. That we shouldn’t establish the pshat in the Gemara based on the opinions of experts who understand these materials.
2. That the Rambam writes that istis (woad) is weaker than chilazon techeiles.

Based on this, he dismissed the question, claiming that the Rambam already states that k’la ilan is weaker than chilazon techeiles. But I don’t understand his reasoning at all—why shouldn’t we consult experts when trying to understand a sugya in the Gemara? If their explanations don’t contradict the words of Chazal, why shouldn’t we accept them? And in truth, there is no contradiction between what the experts say and what Chazal say in the Gemara. Because if the techeiles dye is a different chemical substance than k’la ilan, then it makes sense that the test would work to differentiate them. That would actually fit well with the Rambam’s statement that k’la ilan and istis are weaker than the dye from the chilazon. So there’s no contradiction at all between the Gemara and modern chemistry—the only contradiction is with the position of Murex trunculus supporters. That’s why they wave away the question without answering it, but the question remains strong.

And what the Murex trunculus supporters bring as a proof from non-Jewish historical sources—that plant-based dyes fade when ironed, whereas the Murex trunculus dye does not—this has nothing to do with k’la ilan! These sources are only discussing the purple dye from the Murex trunculus, saying that plant-based purple fades while Murex purple doesn’t. That has no connection to k’la ilan, which might actually be just as strong as the Murex trunculus dye.

And what they bring from the Radbaz (Chelek 2, Siman 625)—that techeiles was forgotten because they discovered a way to dye with k’la ilan that wouldn’t fade from ironing—anyone who actually looks inside the Radbaz will see that he says no such thing! He only writes that the non-Jews had no need for techeiles from the chilazon because they had k’la ilan and could dye it using a technique that made it resistant to ironing. It’s possible that even in the times of Chazal, they had such a method, but techeiles from the chilazon was still stronger and more durable. However, most people didn’t need it so much since k’la ilan usually doesn’t fade from ironing anyway, as the Gemara in Bava Kama 93b states. In any case, in my opinion, the test mentioned in the Gemara is a powerful proof that chilazon techeiles is a different chemical from k’la ilan—because otherwise, the test wouldn’t work, exactly as the dyeing experts explained.

And in Shabbos 26a, it says that Nevuzaradan left behind yogvim, meaning chilazon hunters, between Sulama d’Tzur and Haifa. The Murex trunculus supporters bring this as a major proof for their position, but I don’t understand why. After all, in Matpachas Seforim by Rabbi Yaakov Emden (Perek 4), he writes that this statement in Chazal proves that the fish used for dyeing techeiles was only found in these two locations. The Korban HaEidah on Yerushalmi Shabbos 7:2 says the same thing—that the chilazon wasn’t found anywhere else. The Radal (Pirkei D’Rebbi Eliezer 18:5) also writes that it was only found in Eretz Yisroel, in the portion of Zevulun. The Chasam Sofer on Shabbos 26a (d”h “Eilu”) also clearly holds that the chilazon was only found in Eretz Yisroel, not in chutz la’aretz.

All of this goes against what the Radbaz wrote—that techeiles was found in Yam Suf. But the Chida (Nachal Kedumim, Terumah 25:4) already rejected the Radbaz’s position based on the Sifri, Rambam, and other sources, and he held that the chilazon was only found in the Mediterranean Sea.

And even if one wants to hold like the Radbaz and say it was found in chutz la’aretz, it still wouldn’t match the Murex trunculus, since that species isn’t found in the Red Sea. So this would actually be another proof against the Murex trunculus! In any case, even if you want to say it was found outside of Eretz Yisroel, it still wouldn’t be limited to Sulama d’Tzur and Haifa, since today it’s hunted even in the southern parts of Eretz Yisroel, and archaeological evidence has been found in other places in the south, like Tel Dor. This is yet another proof against the Murex trunculus being the true chilazon.

Here’s the mareh it translation in yeshivish normal English:

And there are a few more proofs on this, but ain kan makom leha’arich. Besides everything mentioned above, a major factor in psak halacha is the position of Gedolei Yisroel. The reality is that the overwhelming majority of Gedolei Yisroel did not accept the Radzyner Rebbe’s techeiles, even before it was proven that its color was fake. Even though in his seforim he brought many strong proofs from Chazal, Rishonim, Acharonim, and even non-Jewish sources, still, Gedolei Yisroel did not take his position seriously at all, as is evident from the Yeshuos Malko and the comments of Rav Yosef Zecharia Stern. Similarly, the Beis HaLevi and Rav Yehoshua Leib Diskin did not accept it, even after the Radzyner Rebbe proved to them that there was no clear mesorah against his techeiles—his argument being that the fish and the dyeing process had simply been forgotten (which is exactly the same argument used today by Murex trunculus supporters). Clearly, their position was that mesorah is required for restoring this mitzvah, as was said in the name of Rav Velvel Brisker zt”l.

The Aruch HaShulchan (O.C. 10:12) writes about that techeiles:
“Know that a few years ago, someone prided himself on discovering the chilazon and making techeiles from it, and he managed to convince a few people to follow him. But he found no support among the Gedolei HaDor and among Klal Yisroel, and the matter was abandoned—until the coming of Moshiach, bimheira b’yameinu.”
And this was before it was proven to be a fake! The Yeshuos Malko and other Acharonim clearly write that the Midrash should be taken literally—that techeiles was hidden away—and that a mesorah is needed to bring it back. All the reasons given back then against the Radzyner’s techeiles apply equally to today’s claims. So, it seems obvious that the Gedolei Yisroel of the previous generation would not have accepted today’s techeiles either.

And go look at the opinion of the majority of Gedolei Yisroel today. Maran Rav Yosef Shalom Elyashiv zt”l in Kovetz Teshuvos (Vol. 1, Siman 2) quotes the Yeshuos Malko, saying that for over a thousand years, Klal Yisroel held that techeiles was hidden away. He writes that the Sifri in Parshas V’Zos HaBeracha and the teachings of the Arizal indicate that techeiles will only return in the time of the Beis HaMikdash. See there at length.

Maran Rav Chaim Kanievsky zt”l in Daas Noteh (Vol. 2, Simanim 273–279) also holds that the simple reading of the Midrash is that techeiles was hidden away and completely rejects the possibility of having techeiles in our time. He writes that it is certainly not techeiles, and that it is better not to wear it, so that people don’t mistakenly think it is real techeiles. His words imply that this was also the view of the Chazon Ish.

Rav Nissim Karelitz zt”l in Chut Shani (Hilchos Tzitzis, Siman 9:6) quotes the Chazon Ish as holding this way.

I also heard from my Rebbi, Rav Shmuel Kamenetsky shlit”a that he sees no reason at all to say that this is the chilazon of techeiles, and he pointed to the Aruch HaShulchan’s words above.

I also heard that Rav Dovid Feinstein zt”l held that a mesorah is required, and without it, one should not wear it, even as a safek.

This is also the clear position of Teshuvos V’Hanhagos (Vol. 4, Siman 5; Vol. 6, Siman 5), where he discusses the issue at length.

And my Rebbi, Rav Avraham Auerbach shlit”a, writes:
“Several talmidei chachamim have concluded, after much research, that they have merited to rediscover techeiles. Yet, despite this, most yirei’im and chareidim le’dvar Hashem are not inclined to accept their conclusions. The Gedolei HaPoskim of our time currently reject this discovery and do not even consider it significant enough to act upon as a safek. Of course, in a matter as serious as a Torah obligation, the final decision must be left solely to the true poskim.”

If this theory fit perfectly with Chazal and Rishonim without difficulty, then maybe there would be room to discuss the issue of mesorah. But since it does not fit Chazal without forcing it, and since not a single Rishon fits with the Murex trunculus without having to stretch their words, and since one has to reinterpret many Rishonim and reconcile multiple contradictions, and in the process claim that our Rishonim were factually mistaken—then I simply do not understand why anyone would choose to follow this, rather than follow the majority opinion of Gedolei Yisroel, who currently reject this position outright.

May Hashem grant us the merit to serve Him with truth and sincerity, to fulfill all of His mitzvos completely, and may Hashem guide us on the right path.

And I remain, your devoted friend,
With great respect,

Doniel Osher HaKohen Kleinman