From Ptil Tekhelet:
This method defines a chulyah as between 7 and 13 twists. There are five (double) knots, with chulyot between them of twists that alternate between Tekhelet and white. The first and last twist of each chulyah is white.
Comments by Rafi Hecht:
This is a method open to a lot of interpretation since Raavad holds 7-13 to refer to winds and not Chulyos. The second Chulya is practically non-important: it allows for all winds to be white for 7-8-11-13, it also allows for more than 13 winds in the event one needs to get a good 1/3rd-2/3rds ratio.
The second Chulya in this case is all white since, as 8 is an even number, it’s not physically possible to have Techeiles winds included and, at the same time, have the first and last winds white.
השגת הראב”ד למשנה תורה הלכות ציצית פרק א’ הלכה ז
ולוקח חוט אחד מן הלבן וכו’ עד בארבע הכנפות. כתב הראב”ד ז”ל /א”א/ זה הסדר אין לו שרש ולא ענף ולמה יותר בתכלת מבלבן שהוא מין כנף וממנו מתחיל ובו מסיים ובכריכותיו הוא ממעט אין זה כי אם שגיון גדול, והגאון רב נטרונאי ז”ל סידר אותו יפה סידור נאה מאד על דרך שאמרה ההלכה, וכמה שיעור חוליא כדי שיכרוך וישנה וישלש אתכלת קאי, ותנא דתנא הפוחת לא יפחות משבעה על הכריכות קאי שהן שלש מן התכלת וארבע מן הלבן מפני שמתחיל בלבן ומסיים בלבן, קושר תחלה סמוך לכנף קשר אחד בחוט לבן ובחוט של תכלת והוא שנקרא קשר העליון ואחר כך כורך שני חוטין אחד של לבן ואחד של תכלת עד שש כריכות והשביעית לבן לבדו וזהו שבע שאמרנו והן חוליא אחת ואלו הכריכות כולן על ששה החוטין המשלשלים והמשולשלים בכנף ובענין זה עושה ה’ קשרים ובין כל קשר וקשר חוליא של שבע כריכות כאשר אמרנו, ונהגו לעשות חוליא אחת בשני קשרים סמוך לכנף ושתי חוליות בסוף הגדיל עם שלשה קשרים ובאמצע כורך בלא דקדוק בין מכונס בין מפוזר בתכלת ולבן עכ”ל.
- A “Single White and Blue Cord Knot” is made by taking one white strand and one blue strand from the eight strands, then while holding them together, wrap them once around the remaining six strands and tucking in the ends in the wrap.
- A “Chulya” is made by taking one white strand and one blue strand from the eight strands, then while holding them together, wrap them three times around the remaining six strands – start with white on top (closest to the garment). The final (seventh wrap) is made by dropping the blue strand from the “wrapping pair” and wind one more time using only the white strand. The “wrapping pair” strands are designated “Shamashim” and are used for all subsequent chulyot (though it is not halachically imperative that the same Shamashim be used).
Real name: R’ Avraham Ben David.
The Baal HaIttur refers to him as “HaRav Krovno” (see https://www.halachipedia.com/index.php?title=Baal_HaIttur)
Abraham ben David (c. 1125 – 27 November 1198), also known by the abbreviation RABaD (for Rabbeinu Abraham ben David) Ravad or RABaD III, was a Provençal rabbi, a great commentator on the Talmud, Sefer Halachot of Rabbi Yitzhak Alfasi and Mishne Torah of Maimonides, and is regarded as a father of Kabbalah and one of the key and important links in the chain of Jewish mystics.
RABaD’s maternal grandfather, Rabbi Yitzhak b. Yaakov Ibn Baruch of Mérida (1035–1094), who had compiled astronomical tables for the son of Shemuel ha-Nagid, was one of five rabbis in Spain renowned for their learning. Concerning the oral history of his maternal grandfather’s family and how they came to Spain, the RABaD wrote: “When Titus prevailed over Jerusalem, his officer who was appointed over Hispania appeased him, requesting that he send to him captives made-up of the nobles of Jerusalem, and so he sent a few of them to him, and there were amongst them those who made curtains and who were knowledgeable in the work of silk, and [one] whose name was Baruch, and they remained in Mérida.”
RABaD was born in Provence, France, and died at Posquières. He was the son-in-law of Abraham ben Isaac of Narbonne Av Beth Din (known as the RABaD II). He was the father of R’ Isaac the Blind, a Neoplatonist and important Jewish mystical thinker. The teachers under whose guidance he acquired most of his Talmudic learning were R’ Moses ben Joseph and R’ Meshullam ben Jacob of Lunel.
RABaD remained in Lunel after completing his studies, and subsequently became one of the city’s rabbinical authorities. He went to Montpellier, where he remained for a short time, and then moved to Nîmes, where he lived for a considerable period. R’ Moses ben Judah refers to the rabbinical school of Nîmes, then under RABaD’s direction, as the chief seat of Talmudic learning in Provence.
The center of the RABaD’s activity was Posquières, after which place he is often called. The town is known as Vauvert today. It is difficult to determine when he moved to Posquières; but about 1165 Benjamin of Tudela, at the outset of his travels, called upon him there. He spoke of the Ravad’s wealth and benevolence. Not only did he erect and keep in repair a large school-building, but he cared for the material welfare of the poor students as well. To this date in Vauvert a street exists with the name “Rue Ravad.” His great wealth brought him into peril of his life because, to obtain some of it, Elzéar, the lord of Posquières, had him cast into prison, where, like Rabbi Meir of Rothenburg, he might have died, had not Count Roger II Trencavel, who was friendly to the Jews, intervened, and by virtue of his sovereignty banished the lord of Posquières to Carcassonne. Thereupon the Ravad returned to Posquières, where he remained until his death.
Among the many learned Talmudists who were his disciples in Posquières were Rabbis Isaac ha-Kohen of Narbonne, the first commentator upon the Jerusalem Talmud; Abraham ben Nathan of Lunel, author of HaManhig; Meir ben Isaac of Carcassonne, author of Sefer haEzer; and Asher ben Meshullam of Lunel, author of several rabbinical works. Raavad’s influence on Jonathan of Lunel also is evident, though the latter did not attend his lectures.