The Mishnah Berurah (Hebrew: משנה ברורה‎ "Clarified Teaching") is a work of halakha (Jewish law) by Rabbi Yisrael Meir Kagan (Poland, 1838–1933, also known as Chofetz Chaim). It is a commentary on Orach Chayim, the first section of the Shulchan Aruch which deals with laws of prayer, synagogue, Shabbat and holidays, summarizing the opinions of the Acharonim (post-Medieval rabbinic authorities) on that work. The title Mishnah Berurah is a reference to the portion in Deuteronomy where Israel is commanded to inscribe God's commandments in large clear writing on a mountainside.