Rabbi Alexander Moshe Lapidot was born in Vilna on 2 Adar 5579 (1819), the son of Rabbi Tzvi Lapidot, one of the community's scholars. So great were his gifts that he was called "the prodigy of Vilna". While still a youth he sent a letter of Torah to Rabbi Akiva Eiger, the giant of the generation.

At twelve he was betrothed to the only daughter of a wealthy man of Jonava, who undertook to support him so that he could learn. At fourteen he went to study at the yeshiva of Salant under Rabbi Tzvi Hirsch Broida. There he formed a close friendship with Rabbi Yisrael Salanter; he later supported the Mussar movement and helped publish the ethical work Etz Pri.

Appointed rabbi of Jonava at seventeen, he later served for many years as rabbi of Rasseyn (Raseiniai), Lithuania. A contemporary of Rabbi Yitzchak Elchanan Spektor, he was one of the Torah giants of a generation rich in them. An eloquent speaker and prolific writer, he was a man of great purity of heart and mind, and lived in poverty.

He passed away in Rasseyn on 10 Adar 5666 (1906). His Mussar work, Divrei Emet, appeared posthumously in Vilna in 1910.