He was best known as the Baal Shem Tov's grandson and for the work Degel Machaneh Ephraim, first published in Korets, 1810.
Moshe Chaim Ephraim was one of three sons of Udl, the beloved daughter of Rabbi Israel "Baal Shem Tov".
Brought up in the household of the Baal Shem Tov, at five years-old he was referred to as a great genius ("ilui gadol b'tachlis halimud") by his grandfather.
After the Baal Shem Tov's death in 1760, he studied under R. Dov Ber the Maggid of Mezerich and under R. Yaakov Yosef of Polonoye.
A classic of Chasidic literature, it contains discussions about each of the weekly Torah portions based upon the teachings of the Baal Shem Tov and his other teachers.