Letter by Rabbi Yitzchak Waldshein, HY"D, Mashgiach Ruchani of Novhardok Yeshiva in Bialystok.
This letter was written by giant of Musar, Rav Yitzchak Elchonon Waldshein to his friend Rav Benzion Bruk the Rosh yeshiva of the Novhardok Yeshivas Bais Yosef in Yerushalayim.
It is a rather lengthy letter written on both sides of a large sheet of paper. He covers several topics including introducing Musar to new Talmidim, a request to buy Seferim, distribution of Novhardok Musar pamphlets, and Tefillin Parshios which the Chazon Ish had sent him.
Harav Hagaon Reb Yitzchak Elchonon Waldshein HY"D (5654- 5703; 1894-1943), known as "Der Sharshever" was a Talmid Muvhak of the "Alter of Novhardok," Reb Yosef Yozel Horowitz ZTK"L. He married the daughter of Rabbi Raphael Alter Shmuelevitz, the son in law of his Rebbe the Alter of Novhardok and father of Rav Chaim Shmuelevitz. Rav Waldshein was the Mashgiach and great Mashpia in several branches of the Novhardok Yeshiva in Pinsk, Ostrovitza, and Bialystok and for a significant amount of time in Baranowitz. He was killed by the Nazi's in 1943. Some of his Drashos and biography were preserved in Sefer "Toras Yitzchak" published in Bnei Brak in 5734 (1974).
His brother in law, the famous Rabbi Chaim Shmuelevitz wrote in his letter of approbation for Toras Yitzchak that Reb Yitzchak was "one of the greatest Masters of Musar and Yireh before WWII. He also was a Baal Mechadesh in Musar.... taught lofty matters of wisdom and Musar as heard from our grandfather Rav Yosef Yozel Horowitz, the "Alter fun Novhardok."