JACOB HA-KOHEN BAR MORDECAI

JACOB HA-KOHEN BAR MORDECAI, gaon of Sura, 797–811. A student of yehudai gaon and Ḥanina Kahana b. Huna , Jacob was held in high esteem. He is credited by some with the authorship of Seder Tanna'im (ed. by Z. Kahana, 1935), one of the most important works on the history and methodology of mishnaic and talmudic literature, and the first of its kind. In his decisions Jacob tended to be as lenient as possible in the interpretation of the law. One of his most important decisions concerned the talmudic rule that, whenever R. Judah ha-Nasi 's opinion is cited in opposition to only one of the sages, Judah's opinion prevails. Jacob, however, decided – in accordance with another talmudic formula – that if Judah's opponent was his father and teacher rabban simeon b. gamaliel , the latter's opinion is accepted. His responsa are written in Hebrew interspersed with Aramaic. His son Moses (Mesharsheya) was also gaon of Sura. -BIBLIOGRAPHY: Z.W. Wolfensohn (ed.), Ḥemdah Genuzah (1863), 3a no. 15; Abraham b. Isaac of Narbonne, Sefer ha-Eshkol, ed. by Z.B. Auerbach, 1 (1868), 91; Halevy, Dorot, 3 (1923), 241; J. Mueller, Mafte'aḥ li-Teshuvot ha-Ge'onim (1891), 73f.; S. Assaf, Tekufat ha-Ge'onim ve-Sifrutah (1955), 147f.; L. Ginzberg, Geonica, 2 (1909), 86. (Meir Havazelet)