Yahrtzeit of Rabbi Aryeh Leib Gunzberg (1695-1785), popularly known by the title of his book of responsa, Sha'ages Aryeh (the Lion's Roar). Rabbi Gunzberg was born in Minsk, served as rabbi in the town of Voluzhin and later in Metz. His writings, marked by their brilliant insight and depth, are studied widely today.