HOROWITZ, ISAIAH (c. 1555—c. 1630), Jewish rabbi and mystic, was born at Prague, and died at Safed. He held various rabbinates, notably at Frankfort-on-the-Main (c. 1606) and at Prague (1614) . From 1621 onwards he lived in Palestine. In 1625 he was imprisoned by the pasha but, on being ransomed, settled in Safed, at that time the home of Jewish Kabbala. Horo witz's largest work, Shelah (abbreviated from the initials of the full title Shene luhoth ha-berit, "Two Tables of the Covenant") is a compilation of ritual, ethics and mysticism. It has been often reprinted, especially in abbreviated form. His prayer book is also marked by cabalistic doctrines.