ISAIAH HOROWITZ ( c. 1 555 - c. 1630), Jewish rabbi and mystic, was born at Prague, and died at Safed, then the home of Jewish Kabbala. His largest work is called Shelah (abbreviated from the initials of the full title Shene luhoth ha-berit, " Two Tables of the Covenant"). This is a compilation of ritual, ethics and mysticism, and had a profound influence on Jewish life. It has been often reprinted, especially in an abbreviated form.
For an account of the Jewish mystics at Safed see S. Schecter, Studies in Judaism, series ii. (1908).