Rav Yitzchok Blazer was born in Shnipshok, near Vilna, on Rosh Chodesh Adar 5597/1837. His father was Rav Shlomo. Rav Yitzchok was a child prodigy, and when he was just fourteen, his father published a kuntres of his chiddushim.
After his marriage at the age of fifteen, Rav Yitzchok moved to Kovno. He learned in the Bais Medrash of Rav Yisrael Salanter.
At twenty-five, by order of Rav Yisrael, Rav Itzele, as he was fondly known, was appointed Rav of Petersburg, a position he held for sixteen years. He is called after that city.
Subsequently, he returned to Kovno. In 5636/1876, Rav Yisrael Salanter had established a kollel there; its purpose was to produce Rabbonim and Dayonim by supporting and guiding exceptional Talmidei Chachomim. The project received the blessing and support of Rav Yitzchok Elchonon Spector, Rav of Kovno. It was joined by such luminaries as Rav Naftoli Hertz (later Chief Rav of Yaffo), Rav Naftoli Amsterdam, Rav Chaim (Telzer) Rabinowitz, and Rav Yosef Yoizel Horwitz, the “Alter of Novardok”, among others.
The kollel was eventually named Kollel Knesses Bais Yitzchok, in memory of Rav Yitzchok Elchonon. The true glory of the kollel was realized under the leadership of Rav Yitzchok Blazer, whose rousing lectures were the kollel’s life force.
As one of the leading and most famous talmidim of Rav Yisrael Salanter, founder of the Mussar movement, it was to be expected that after Rav Yisrael’s petira, Rav Yitzchok would become his successor.
Rav Yitzchok spent the last few years of his life in Yerushalayim, where Rav Shmuel Salant requested his help with community affairs.
Rav Yitzchok was niftar on the eleventh of Av 5667/1907 at the age of seventy, and was buried on Har HaZeisim.
Rav Chaim Berlin related that Rav Yitzchok left a request that no hespeidim be delivered for him. Rav Chaim Berlin asked Rav Shmuel Salant if they were required to abide by the humble last wishes of Rav Yitzchok Blazer, since it would be meritorious to be maspid a person of his stature. Rav Shmuel Salant ruled that indeed they were obligated to heed his final wishes. A few days after his petira, Rav Chaim Berlin related that Rav Itzele came to him in a dream and thanked him for honoring his request.
Rav Chaim then asked Rav Itzele what issues of halocha the Bais Din Shel Ma’ala is stringent about. Rav Itzele told him that a human being cannot fathom the depth and detail of the Heavenly judgment. They were particularly exacting on the purity of a person’s speech. This, coming from a person who had mastered the art of silence!
Rav Yitzchok wrote Pri Yitzchok on Shas and also brought to print Ohr Yisrael, the derashos in mussar of Rav Yisrael Salanter.
Zecher Tzaddik livrachah.
