Aaron Chorin (Choriner, 1766–1844), was a pioneer of Reform Judaism in Hungary. Born in Hranice (Moravia), Chorin studied for two years in the yeshivah of Mattersdorf and then at that of R. Ezekiel Landau in Prague, where in addition to his religious studies, he acquired a knowledge of general philosophy and developed an interest in Kabbalah. He was appointed rabbi of Arad in 1789, and in 1803 published in Prague his Emek ha-Shaveh, attacking those customs which he declared had no basis in Judaism, basing his reforms on rulings in the Talmud. The book caused a storm among the ultra-Orthodox, who found it heretical. Mordecai Banet of Nikolsburg appealed to the community of Arad to ban the book. Chorin was summoned to appear before a bet din who ordered the book to be burned and who compelled him to recant in writing. However, Chorin appealed to the government, which set aside the verdict. Chorin began by abrogating customs such as kapparot and placing copies of the Psalms of Ascent near a woman in childbirth, but in the course of time he extended his reforms, particularly to the synagogal liturgy, abolishing the Kol Nidrei prayer, changing the text of other prayers, permitting prayer in the vernacular with uncovered head, and approving the use of the organ on the Sabbath. He also curtailed the seven days of mourning and permitted riding and writing on the Sabbath.

שערים נוספים: איין ווארט צו זיינער צייט איבער דיא נעכסטענליב אונד דען גאטטעסדינסט. נאך דעם פאן העררן אהרן חארי אבער-ראבבינער אין אראד פערפאסטען דבר בעתו ... Ein Wort zu seiner Zeit, ueber die Naechstenliebe und den Gottesdienst. Nach dem Herrn Aron Chorin Ober-Rabbiner in Arad verfassten ... דבר בעתו