JACOB BEN NATHANAEL IBN AL-FAYYUMI (the name is given in this form in "Maẓref la-Ḥokmah," fol. 93a; in Neubauer, "M. J. C." [Sambari] i. 122, 24; and in Nahum's Hebrew version of Maimonides' "Letter" cited below):
By: Richard Gottheil
Rosh yeshibah of the Yemen Jews in the second half of the twelfth century. All that is known of him is that at the suggestion of Solomon ha-Kohen, a pupil of Maimonides, he wrote to the latter asking his advice in regard to a pseudo-Messiah who was leading the Jews of southern Arabia astray. From a passage in Maimonides' "Letter to the Wise Men of the Congregation of Marseilles," the date of Jacob's letter is fixed as 1172 (Halub, in his ed. of "Iggeret Teman," p. 51, note). In answer, Maimonides sent his "Iggeret Teman," or, as it is also called, "Petaḥ Tiḳwah." Harkavy supposes that Jacob had cognizance of Saadia's "Sefer ha-Galui" ("Studien und Mittheil." v. 154; comp. "Monatsschrift," xliv. 508). Jacob's father was known as a philosophical writer (see
