The twentieth of the month is the yahrzeit of the erudite chassid and Kabbalist, R. Levi Yitzchak Schneerson (father of the Rebbe Shlita) — son of R. Baruch Shneur, son of R. Levi Yitzchak, son of R. Baruch Shalom, eldest son of the Tzemach Tzedek. R. Levi Yitzchak was imprisoned and exiled for his work in strengthening and spreading Yiddishkeit, and died in exile on the 20th of Menachem Av, 5704 (תש"ד; 1944) in Alma Ata, in the USSR province of Kazakhstan.1

It is the custom of the Rebbe Shlita to mark this date by a farbrengen, which he opens — if it falls on a weekday — with a siyum, the festive completion of a tractate that he has studied.

On the 20th of Menachem Av in 5724 (תשכ"ד; 1964), which was the twentieth yahrzeit of the passing of his father, of blessed memory, the Rebbe Shlita founded a loan fund, Keren Levi Yitzchak, in his name.2