R. Jacob ben Hayyim Zemah (d. after 16 65), belonged to a Converso family in northern Portugal, where he served as a physician. He fled that land for Erez Israel, passing through Salonika where he studied Torah. Some time between 1610 and 1620, he settled in Safed and learned Talmud and Kabbalah. In approximately 1628 he left for Damascus, and studied the Lurianic Kabbalah under R. Samuel ben Hayyim Vital for eighteen years. Around 1640 he settled in Jerusalem where he became one of the leading kabbalists. He opened a yeshiva, counting among his students R. David Comforte. R. Zemah was among the Jerusalem opponents of Shabbetai Zevi who excommunicated him when he first claimed to be the messiah in 1665.

His many works are anthologic in character, relying on R. Hayyim Vital’s Kabbalah. Nevertheless, R. Zemah’s contribution to the literary consolidation of Lurianic Kabbalah is important as are his citations of contemporary kabbalists, e.g., R. Joseph ibn Tabul. Zemah left many works, partly in manuscript. In the aforesaid introduction he gives details of his literary activities. His works include Zohar ha-Raki'a (Korzec, 1785), a commentary on sayings of Sifra di-Zeni'uta, and the Idra of the Zohar; Zer Zahav, an explanation of every item in the Orah Hayyim section of the Shulhan Arukh according to the Zohar and the Lurianic Kabbalah; Lehem min ha-Shamayim (Munkacs, 1905), a compilation of Lurianic customs of which the printed version differs from the manuscripts; Nagid u-Mezavveh (Amsterdam, 1712), an important anthology of Lurianic customs which served as the basis for Shulhan Arukh shel ha-Ari; Zemah Zaddik (Korzec, 1785), kabbalistic homilies.