Hebrew name: אבני נזר
Years: 1838–1910
Primary city: Sochaczew
Rabbi Avraham Borenstein was a leading Polish posek and the first Rebbe of the Sochatchov Chasidic dynasty. His responsa collection, Avnei Nezer, and his work on the melachos of Shabbos, Eglei Tal, are recognized for their depth and analytical approach, making them foundational texts in rabbinic study.