- 1. Tanna of the second century; probably identical with Jacob b. Ḳorshai (= "the Ḳorshaite," or "of Ḳorsha"), the contemporary of Simon b. Gamaliel II. Of his relations with this patriarch the Talmud has preserved the following incident: Nathan the Babylonian and Meïr had determined to humiliate Simon and bring about his deposition by putting to him questions on 'Uḳẓin, which he had not mastered; but Jacob prevented the patriarch's discomfiture by indirectly turning his attention to the neglected treatise (Hor. 13b). He was a grandson of Elisha ben Abuyah on his mother's side (Ḳid. 39b; Ḥul. 142a), and was a teacher of Judah I. (Yer. Shab. x. 12c).Jacob is frequently met in halakic controversies with Akiba's later disciples (see Tosef., Zeb. x. 9, 11; ib. Tem. i. 17; ib. Ṭoh. vi. 5, 6). Sometimes he cites Meïr as an authority (Tosef., Ma'as. Sh. ii. 10; ib. Yeb. xii. 11). The compiler of the Mishnah cites Jacob (Tosef., 'Ab. Zarah, v. [vi.] 4), and preserves the following eschatological remarks of his: "This world is as if it were a vestibule to the future world: prepare thyself in the vestibule that thou mayest [becomingly] enter the reception-room. One hour devoted to penitence and good deeds in this life is worth more than the whole of the life hereafter [where no opportunity is given for improvement]; and one hour's happiness in the world to come is worth more than all the pleasures of this world" (Ab. iv. 16, 17).In this spirit Jacob interprets the rewards attached to filial reverence and to sparing the dam when rifling a bird's nest: "That thy days may be prolonged, and that it may go well with thee" (Deut. v. 16, xxii. 7). An incident once came under his notice that seemed to falsify this Scriptural promise. A dutiful son, in obedience to his parent's wish, climbed a tree after some birds. He duly complied with the Scriptural requirements, and yet, in descending, he fell and was killed. Thereupon Jacob remarked, "In this world there is no reward for good deeds: the rewards promised will be awarded in the world which is all good and immeasurably long" (Ḳid. 39b). Many decades later a prominent Babylonian amora remarked, "Had Aḥer [Elisha b. Abuyah] interpreted those promises as did his daughter's son he would not have become a sinner" (ib.; comp. Yer. Ḥag. ii. 77b; Eccl. R. vii. 8).Bibliography: Bacher, Ag. Tan. ii. 395; Brüll, Mebo ha-Mishnah, i. 242; Frankel, Darke ha-Mishnah, p. 202; Hamburger, R. B. T. ii.; Weiss, Dor, ii. 171.
- 2. Palestinian amora of the fourth century; contemporary of R. Jeremiah; probably identical with Jacob b. Aḥa (comp. Pes. 91b with Yer. Pes. viii. 36a, B. M. 101a with Yer. B. Ḳ. ix. 6d, and 'Ab. Zarah 13b with Yer. 'Ab. Zarah i. 39d).