Rabbi Moshe Greenberg, director of Chabad-Lubavitch of Bnei Brak and noted for continuing Jewish education activities despite a ban under Communist rule, passed away on Tuesday at age 84.

Rabbi Greenberg passed on the eve of Yud-Beis Tamuz, the anniversary on the Jewish calendar celebrating the release of the sixth Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneerson — his mentor — from prison in the Soviet Union. The date of his passing is ironic, in that Rabbi Greenberg himself was also imprisoned by Soviet authorities, albeit under less harsh circumstances.

Born into a Chassidic family in Kishinev, Moldova, Greenberg was secretly tutored in Jewish studies by his father till age 14 and then sent to an underground Chabad-Lubavitch yeshiva in Tashkent, Uzbekistan.

At the yeshiva, he learned of the plan of the sixth Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneerson of righteous memory, to keep Judaism alive through a network of activists and rabbis spreading the knowledge quietly among Jews, despite the oppressive Communist regime.

Many were jailed, or exiled to Siberia – including the Rebbe himself, and Rabbi Greenberg. He and his friends were caught trying to escape the Soviet Union at the end of World War II, and sent to Siberia for seven years.

In 1951, before the High Holy Days, he asked an engineer who looked Jewish if he could somehow get a machzor (a special holiday prayer book) into the camp. The man knew of only one copy, and it belonged to someone else. The rabbi asked to borrow it so as to copy down the prayers.

In a book entitled “My Father’s Machzor,” Greenberg’s son writes that his father built a large wooden crate into which he crawled for a few hours every day. “There, hidden from view, he copied the book, line for line, into a notebook. After a month, he had copied the entire machzor,” wrote Rabbi Zushe Greenberg.

The imprisoned rabbi used his handwritten machzor to serve as canto in the camp, reciting each prayer, repeated by other Jews in low, solemn voices.

After nearly seven years, Greenberg was released in 1953 along with other political prisoners upon the death of Joseph Stalin, according to Chabad.org . He took only his machzor with him.

Shortly after his release, Greenberg married Devorah Chazan.

In 1967, the family was permitted to immigrate to Israel, and went straight to Bnei Brak.

Many of the couple’s 17 children became Chabad-Lubavitch emissaries in Israel, the United States and elsewhere around the world, in places such as Shanghai, Ukraine, France and Germany.