Rabbi in Galicia. He served as rabbi first in the town of Potok and then in Brezen. He is best known for his responsa, four volumes of which were published during his lifetime and three after his death. His rulings on Jewish law were widely accepted as authoritative and essential in coping with the practical problems of the time in which he was active. A modest and kindly man, he adhered stringently to the requirements of Jewish law but endeavored to reach as lenient decisions as possible in religious questions addressed to him.