Chatham Sofer - Yoreh Deah.

R. Moshe Unger (d. 1897) was the son of R. Mordechai David Unger of Dombrova, a disciple of the Maggid of Koznitz and the Chozeh of Lublin. He was the son-in-law of R. Chaim Halberstam of Sanz, marrying his daughter Miriam. He later became his father-in-law’s uncle as well, when R. Chaim Sanzer married R. Moshe’s young niece as his third wife. After forty years alongside R. Chaim Sanzer, R. Moshe eventually emigrated to Tzfath where he is buried. The name “Horowitz” on the title probably refers to the family of R. Moshe’s son-in-law, R. Naphtali Chaim Horowitz of Dzikov, author of Minchah Chadashah who later resided in Jerusalem. For more details concerning R. Moshe Unger and his family, see: N. M. German, Ne’emnu Meod (2006) pp. 56, 70-71, 76. It should be noted that both present Bobover Rebbes are descendents of R. Moshe Unger.