Karo, Isserles and One Code for Two Worlds

The Shulchan Aruch nearly divided the Jewish world it ended up uniting. Karo, an exile from Spain writing in the kabbalistic centre of Safed, decided the law by majority vote among his three pillars, Alfasi, Maimonides and Asher ben Yechiel. Two of the three were Sephardic authorities, and the resulting code often ruled against the customs of Ashkenaz.

In Krakow, Rabbi Moses Isserles, the Rema, had been preparing a code of his own; on seeing Karo's work he chose annotation over rivalry. His glosses, printed in the text in a different typeface from the 1570s onward, record wherever Ashkenazic practice differs, invoking the principle that established custom has the force of law. He called them the Mapah, the Tablecloth spread over Karo's Set Table, and the shared metaphor was apt: one table now served two worlds, with Sephardic and Mizrahi communities generally following Karo's plain text and Ashkenazic communities following the Rema's gloss. Around this joint text grew rings of standard commentaries, the Shakh and Taz on Yoreh De'ah, the Magen Avraham on Orach Chayim and many others, and later restatements such as the Mishnah Berurah track its chapter numbers. To rule from within its frame remains the ordinary meaning of deciding Jewish law.