(Shach) Rabbi Shabtai HaKohen

The Shach was one of the greatest halakhic commentators on the Shulchan Aruch. His commentary became especially central on Yoreh De’ah, the section dealing with laws such as kashrut, ritual purity, vows, and other areas of Jewish practice.

His rulings became essential in later halakhic decision-making. Together with other major commentators, the Shach helped turn the Shulchan Aruch into a living legal system studied through layers of debate and interpretation.