ר' יצחק מדורא

Rav Yitzchak ben Rav Meir HaLevi of Düren, known as the Baal Sha’arei Dura, was among the rabbanim of Ashkenaz and one of the baalei haTosafot. In his youth he learned in the yeshiva of Birona in Burgundy before Rav Tuvia ben Rav Eliyahu of Vienne, and his son Rav Alexandri gave testimony that his father was present there when Rav Yechiel of Paris came through on his journey to Eretz Yisrael — which places his birth in the years around 1220–1240. He learned also before the Maharam of Rothenburg. He was in contact with the Rosh, and at times the two signed teshuvot together. He married Pura, daughter of Rav Yakar HaLevi bar Shmuel of Cologne.

Sha’arei Dura, the gates of Düren, is the work that carried his name. It sets out the laws of issur v’heter, the kashrut of food, and it served the kehillot of Ashkenaz for generations as the principal text for that learning; even after the Shulchan Aruch and the hagahot of the Rema it kept its standing. It was written for rabbanim to learn from, and a well-known printing appeared in 5294/1534. Later authorities set their notes and explanations upon it, among them Rav Yisrael Isserlein, the Maharshal, Rav Natan Shapiro and the Rema. He also gathered the minhagim of Ashkenaz through the year in a work known as Minhag Dura, and wrote hilchot challah; Zunz attributed to him Tikkun Shetarot, a collection of formulations for gittin and shetarot.

A further section of Sha’arei Dura treats hilchot niddah in brief, and the author says plainly in his introduction how it came to be written: his wife pressed him to set down the laws of niddah for her, and he laid them out in short compass in twenty-eight dinim. Among his talmidim were Rav Alexandri Zuslin HaKohen, author of Sefer HaAgudah, and Rav Shimshon ben Tzadok, author of the Tashbetz Katan.