Rabbi Isser Zalman Meltzer—Even ha-Ezel רבי איסר זלמן מלצר — אבן האזל

He studied in Volozhin under the Netziv and Rabbi Chaim Soloveitchik, then in Radin under the Chafetz Chaim. In 1897 he took over the yeshiva in Slutsk and held it a quarter of a century—through war, revolution and the first years of Soviet rule, until the yeshiva had to be moved across the border to Kletsk.

In 1925 he went up to Jerusalem and became head of Etz Chaim, the oldest yeshiva in the city. There he wrote the Even ha-Ezel—a treatment of the Rambam's Mishneh Torah in the manner of Brisk: not "what is said" but "why thus and not otherwise". The book became one of those by which the Rambam is studied in the yeshivot.

His students were a whole generation of yeshiva heads; his son-in-law was Rav Aharon Kotler, who carried the Lithuanian yeshiva to America. It was said of him that he was among the last who remembered Volozhin alive—and passed it on.