His father Aharon Yitzchak Epstein was a builder and contractor who spend much of his time traveling for his work, which were often projects of the Czarist government.

His original intent was to follow in his father's footsteps: to work as a merchant, while dedicating time to daily Torah study.

[6] In 1864, at the age of 35, Epstein was appointed rabbi of Novozybkov (east of Gomel, now Bryansk region), a town with a large number of Hasidic Jews, mainly adherents of Chabad Lubavitch and Chernobyl.

[7] His major endeavor during this period was writing his first work, Ohr LaYesharim, a commentary to Sefer HaYashar of Rabbeinu Tam.

[9] The Epsteins had 5 children: As a well-known authority of Halakha, many young scholars asked to receive his semicha (rabbinic ordination).