רבינו תם

Rabbeinu Tam was a Rishon and one of the foremost Tosafists, whose opinions are woven through the classic codes of halachah. The supplied passages show him cited again and again as a central voice in halachic dispute — often set alongside Rashi (Rabbeinu Shlomo) and the Rashbam, with his ruling frequently differing from theirs and from the Rambam. He was a grandson of Rashi.

His positions appear across the full breadth of Jewish law. In Yoreh De’ah he is brought on the laws of kilayim (the forbidden mixture of wool and linen), where he holds a stricter view than Rashi, teaching that the prohibition can apply even when the wool and linen were each spun separately and only later joined by weaving, knotting, or sewing. He is also cited in Yoreh De’ah on the laws of items entrusted to a non-Jew. In Even HaEzer his words bear on the laws of kiddushin, and in Choshen Mishpat on the conditions that govern a valid conditional gift. In Orach Chaim he appears on the laws of Pesach — the kashering of ovens and earthenware vessels used with chametz — and on the prohibition of washing on Yom Kippur.

Across these citations Rabbeinu Tam emerges as a sharp and independent halachic authority whose rulings the later codifiers could not pass over, weighing his view in matter after matter alongside the other great Rishonim.