HAMMERSCHLAG, JOSEPH (NATHAN NAT'A ḤAZZAN BEN MOSES NAPHTALI HIRSCH):
Moravian cabalist; lived in the seventeenth century. He was the author of the following: "Or ha-Ganuz," commentary on part of the Zohar (begun in 1648); "Sefer Mo'ade ha-Shem," a treatise on the calendar, beginning with the year 1681 (written at Nikolsburg); cabalistic notes on the prayers, written on the margins of printed copies of the Psalms and of the prayers for the first evening of Rosh ha-Shanah. These three works are extant in manuscript in the Bodleian Library.
- Neubauer, Cat. Bodl. Hebr. MSS. Nos. 2168, 3; 1999, 3; 2277, 1;
- Fürst, Bibl. Jud. i. 360;
- Wolf, Bibl. Hebr. iii. 853.