- JACOB BEN REUBEN
- JACOB BEN REUBEN (12th century), Karaite biblical exegete, probably a native of Constantinople. He traveled to a number of countries to spread Karaism and at the same time tried to collect commentaries, mainly in Arabic, written by his Karaite predecessors. His biblical commentary Sefer ha-Osher is essentially a collection of excerpts from earlier Karaite authors, hence the frequent glosses in Greek and Arabic; some of these writings are otherwise unknown. His knowledge of the khazars and Slavs, whom he mentions, probably derives from the writings of his predecessors. Jacob mainly avails himself of the tenth-century Karaite exegete Japheth b. Ali, simply reproducing passages from his Arabic commentary. The polemics against saadiah gaon and Muslim scholars are also taken from the writings of the Karaite Salmon (Solomon) b. Jeroham . Of the works by Rabbanite authors, Jacob used those of Jonah ibn Janāḥ and dunash ibn labrat . Only his commentary on the Later Prophets (excepting Isaiah) and Hagiographa (excepting Psalms) titled Mivḥar Yesharim has appeared in print (Eupatoria, 1836) together with Sefer ha-Mivḥar by aaron b. joseph (the Elder). -BIBLIOGRAPHY:: S. Poznański, Karaite Literary Opponents of Saadiah Gaon (1908), 66–68; Mann, Texts, 2 (1935), 1275, 1415; Z. Ankori, Karaites in Byzantium (1959), index; M. Steinschneider, Catalog… Leiden (1958), 106–7, 391–2; S. Pinsker, Likkutei Kadmoniyyot (1860), 2nd pag., 80–86; A. Harkavy, Zikkaron la-Rishonim…, pt. 1 book 8 (1903), 152–5. (Isaak Dov Ber Markon)
Encyclopedia Judaica. 1971.