אהרן שמואל קיידנובר

Rav Aharon Shmuel Kaidanover (5374/1614–19 Tammuz 5436/1676), known as the Maharshak, was among the first of the acharonim, whose sefarim are printed in the margins of the Shas itself. Born in Koidanov near Minsk — the name Shmuel was added in a childhood illness — he learned under Rabbi Yaakov of Lublin and then under his son, Rabbi Heshel of Krakow. In Vilna he sat as a dayan on the beit din of Rabbi Moshe Lima, author of the Chelkat Mechokek, alongside Rabbi Efraim HaKohen, author of the Shaar Efraim, and the Shach.

The gezeirot of tach v’tat broke over his life: fleeing the Cossacks he lost his library and his own manuscripts, his two young daughters were murdered, and he was left, as he wrote years later in the preface to Birkat HaZevach, broken and destitute on the road. From that ruin he rose to serve as rav of a chain of great kehillot — Nikolsburg, Glogau, Risha, Fuerth, Brisk and Frankfurt am Main — returning to Poland in 1671 as rav of Krakow. He was niftar on 19 Tammuz 5436 while attending the Vaad of the galil in Chmielnik.

His sefarim became fixtures of learning: Birkat HaZevach on Seder Kodashim; Tiferet Shmuel, chiddushim on the Rosh with hasagot on the Maharsha, printed in editions of the Shas; the responsa Emunat Shmuel; and the derashot Birkat Shmuel. He held that psak should be drawn from the Tur and Beit Yosef rather than from the Shulchan Aruch alone — writing to one rav that he should sell all his sefarim and buy himself a Tur. The Yaavetz wrote that he knew the Turim and Beit Yosef by heart; the Taz cites him, and the Magen Avraham calls him gaon. His son, Rabbi Tzvi Hirsch Kaidanover, author of the Kav HaYashar, printed many of his father’s works.