Penned by Rabbi Yosef Karo in Safed in the 1500s during Ottoman rule, the Shulchan Aruch is the ultimate religious legal code of the Jews. Though the Shulchan Aruch represents the Sephardic tradition, Rabbi Moses Isserles’ Asheknazic legal annotations have been printed in Rashi script alongside Karo’s text in the standard edition, and the Shulchan Aruch is the book always referenced, if not always followed, by most Orthodox rabbis when questions of Jewish law come up. You know the expression “You don’t pasken a Shaila from the Gemara”? We suspect Karo’s publicist had something to do with it.