Rav Shmuel Yitzchak Hillman (1868–1953) was a descendant of his namesake Rav Shmuel Hillman, the Av Beth Din of Metz, and Rav Michal Datnover, a scholar and Kabbalist from Kovno, Lithuania. In his youth, Rav Hillman studied Torah under his uncles, Rav Mordechai Hillman, Av Beth Din of Pasvatin, and Rav Noach Yaakov Hillman of Pasval. In 1897, he became head of the Beth Din of Berazino in Minsk. In 1908, he was appointed Rav in Glasgow, and served the Beth Din there until 1914, when he was appointed a religious court judge at the London Beth Din. Rav Hillman moved to Jerusalem circa 1934. Along with his son-in-law Rav Israel Yitzhak HaLevi Herzog, the Chief Rabbi of Israel, he co-founded the Jerusalem Yeshiva Ohel Torah and served as its Rosh Yeshiva. Rav Hillman authored Or Hayashar, a twenty volume commentary on the Jerusalem and Babylonian Talmud, the Rambam, Sifra and the Mishnaic Orders Zeraim and Taharos.