Portuguese cabalist and physician; died at Jerusalem in the second half of the seventeenth century. He received a medical training in his native country as a Marano, but fled about 1619 to Safed and devoted himself to the Talmud and the casuists ("pose?im") until 1625; then he went to Damascus, where for eighteen years he studied the Cabala from the Zohar and the writings of Isaac Luria and ?ayyim Vital. He finally settled at Jerusalem and opened a yeshibah for the study of the Zohar and other cabalistic works, David CONFORTE being for some time one of his pupils ("?ore ha-Dorot," pp. 36a, 49a). Jacob ?ema? was one of the greatest cabalists of his period and was a prolific author, his works including treatises of his own as well as compilations of the writings of ?ayyim Vital. He produced twenty works, of which only two have been published. The first of these is the "?ol ba-Ramah" (Korez, 1785), a commentary on the "Idra," which he began in 1643, and for which he utilized the commentary of ?ayyim Vital. In the preface to this work he maintained that the coming of the Messiah depended on repentance ("teshubah") and on the study of the Cabala from the Zohar and the writings of Isaac Luria, the delay in the advent of the Messiah being due to the fact that schools for such study had not been established in every town. His second published work is the "Nagid u-Me?awweh" (Amsterdam, 1712), on the mystical meaning of the prayers, this being an abridgment of a compendium which ?ema? composed on the basis of a more comprehensive treatise. Among his unpublished works, special mention may be made of the "Ronnu le-Ya'a?ob," in which he calls himself "the proselyte" ("ger ?ede?"; "Cat. Oppenheimer," No. 1062 Q). This treatise consists of notes recorded while studying under Samuel Vital and supplemented by his own additions. In his compilation of ?ayyim Vital's writings, ?ema? pretended to have discovered many works of Vital which were unknown to the latter's son Samuel.