Rav Baruch Ber Leibowitz—Birkat Shmuel רב ברוך בער לייבוביץ — «ברכת שמואל»

Born in Slutsk, in Volozhin he became a student of Rabbi Chaim Soloveitchik—the one of whom Rabbi Chaim himself spoke as having understood him better than the others. The Brisker way of learning—to analyse not what is said but why so and not otherwise, finding in a dispute two definitions of one thing—he carried into his own lessons whole, without admixture.

From 1904 he headed the Knesset Beit Yitzchak yeshiva in Slabodka—the second Slabodka yeshiva, beside the Alter's school. The war drove the yeshiva to Kremenchug, then to Vilna, and in 1926 it settled in Kamenetz and became "Kamenetz"—one of the great names of interwar Lithuania. He taught slowly: a single lesson could last for weeks, until every word of the Rambam fell into place.

His writings appeared as Birkat Shmuel—in memory of his father; yeshivot still learn from them what is called "Brisker lomdus." At the outbreak of the war the yeshiva fled to Vilna, and there he died in Kislev 1939—without seeing what became of his students and his town.