ר׳ יעקב ישראל עמדין

ר׳ יעקב ישראל בן צבי אשכנזי עמדין (1697–1776), known by the acronym יעב״ץ, was a North German halakhist, critic, printer and one of the most forceful opponents of crypto-Sabbateanism. Born in Altona, he was educated chiefly by his father ר׳ צבי הירש אשכנזי, the חכם צבי, and followed the family through Amsterdam and central Europe. After marriage he lived in Brody and studied in the celebrated kloyz. His only sustained communal rabbinate was at Emden from 1728 to 1733, from which his surname derives. Returning to Altona, he chose relative independence, earning through commerce and a private Hebrew press established in the 1740s. This enabled him to publish responsa, liturgy, textual criticism, grammar, Kabbalah and polemic without ordinary communal controls. His שאלת יעב״ץ and מור וקציעה remain important halakhic works; his siddur combines text, law and commentary, while מטפחת ספרים applies unusually critical analysis to the Zoharic corpus. From 1751 his accusation that amulets of ר׳ יהונתן אייבשיץ contained Sabbatean formulas generated an international rabbinic controversy, bringing bans, civil intervention and intense personal attacks. His autobiographical מגילת ספר is an exceptional, candid source for eighteenth-century rabbinic family and communal life, though also a partisan self-defence. He died in Altona in 1776 and was buried in its Königstraße Jewish cemetery.