Moshe Feinstein

Moshe Feinstein (; Lithuanian pronunciation: ''Moshe Faynshteyn''; ; March 3, 1895 – March 23, 1986) was a Russian-born American Orthodox Jewish rabbi, scholar, and ''posek'' (authority on ''halakha''—Jewish law). He has been called the most famous Orthodox Jewish legal authority of the twentieth century and his rulings are often referenced in contemporary rabbinic literature. Feinstein served as president of the Union of Orthodox Rabbis, Chairman of the Council of the Moetzes Gedolei HaTorah of the Agudath Israel of America, and head of Mesivtha Tifereth Jerusalem in New York.

Feinstein is commonly referred to simply as ''"Reb Moshe"'' (or ''"Rav Moshe"''). Provided by Wikipedia