Letter by R. Aaron Walkin of Pinsk-Karlin (1865–1942), Lithuanian rabbi, communal leader, and author. Born in Shumyachi, Belorussia, R. Walkin received his education at the Volozhin yeshiva where he studied under R. Naphtali Zevi Judah Berlin. After the yeshiva was closed in 1892, he continued his studies in Kovno under R. Isaac Elhanan Spektor. R. Walkin served successively as the rabbi of the communities of Gruzdziai and Seduva in Lithuania, and Mstislavl in Belorussia. After World War I he became the rabbi of the important Jewish community of Pinsk. He was active in Agudat Israel and, with R. Meir Hildesheimer, visited the United States on its behalf in 1914. R. Walkin and most of his family were murdered by the Nazis during the summer of 1942.

R. Walkin was considered a leading writer of responsa of this period, and his published responsa appeared in two volumes under the title Zekan Aharon (1932, 1938; reprinted in the U.S., 1951, 1958). His talmudic novellae Beit Aharon were published in four volumes (to Bava Mezia, 1905, reprinted 1965; to Ketubbot, 1911; to Bava Kamma, 1923, reprinted 1963; to Gittin, 1939, reprinted 1955). R. Walkin also published Hoshen Aharon, a commentary to the Shulhan Arukh Hoshen Mishpat in three volumes (1927, 1928, 1930). His sermons entitled Mezah Aharon were published in two volumes, the first of which was reprinted by war refugees in Shanghai (vol. 1, 1902, 1908, 1928, 1945; vol. 2, 1926). He also issued a new edition of the Sefer Yere'im of R. Eliezer b. Samuel of Metz, which included his own commentary entitled Saviv li-Yre'av (1935, reprinted 1960).