The obituary to Mordechai Epstein stated:

R. Mordechai Epstein was one of the so called “bnei aliyah” [members of elite], the number of which diminishes from generation to generation: the great gvir [wealthy notable], who spent his every free minute for studying Torah, and invested a great deal of energy and money for spreading the knowledge of Talmudic literature among the people. Thus he always supported large and small yeshivas and helped much to strengthen the institutions, which aim to support and reinforce the Orthodox Jewry. Reb Mordechai Epstein’s house was, in general, the house of Torah and philanthropy, which was always visited by the great rabbis […]. Notwithstanding his multiple activities and business obligations, he had found time to write several books on halakhah and agadah under the pen-name “Shaarei Torah” [The gates of the Torah] […].Reb Mordechai Epstein was involved in the Vilna community during his entire life. He served for many years as a gabai at the Talmud Torah, as a committee member of the M. Strashun Library and played a significant part in several other charitable institutions of the local community. […] Thousands went after his coffin and many eulogies were said in the cemetery; people knew and felt that one of the “last” has died.