JACOB B. YAḲAR:
German Talmudist; flourished in the first half of the eleventh century. He was a pupil of Gershom b. Judah in Mayence, and is especially known as the teacher of Rashi, who characterizes him as "mori ha-zaḳen."
Jacob was one of the leading Talmudic authorities of his time, although Rashi sometimes criticizes the opinions of his teacher. It appears that Jacob had already written commentaries on portions of the Talmud before Rashi (e.g., comp. Rashi on Bek. 41a); at any rate, much in Rashi's commentary on the Talmud is derived from oral communications of Jacob, who, in fact, is meant when Rashi says simply "my teacher" without naming any one. It appears also, from a remark of Rashi (commentary to Job xxii. 30), that Jacob was engaged in interpreting the Bible and in the study of Hebrew. Besides Rashi, the German Talmudists Eliakim b. Meshullam ha-Levi and Solomon b. Samson were pupils of Jacob.
- Gross, Gallia Judaica, pp. 300, 506;
- Zunz, Biography of Rashi, Hebrew transl., pp. 7b, 26a, b.