In the 11th and 12th centuries, the center of gravity of Ashkenazi intellectual life was in northeastern France and the Rhineland, although it would gradually move eastward over the course of the subsequent centuries. But Rabbi Isaac ben Moses, who became one of the great medieval experts on Jewish law, was born around 1180 in the German frontier province of Bohemia, and later settled in Vienna—a city almost as distant from the Ashkenazi heartland. He is better known by the name of his major work Or Zaru’a, taken from the verse from the book of Psalms, “Light is sown for the righteous, and gladness for the upright in heart.” Tamar Marvin tells his story:
To its Jewish denizens, Bohemia was known by the unflattering moniker “the land of Canaan,” and so the Or Zaru’a terms his Slavic glosses l’shon Canaan, “the Canaanite language.” Bohemia was indeed something of a hinterland in the 12th century, with its best and brightest finding their way to Regensburg and Prague. It seems that Rabbi Isaac suffered from economic straits and possibly other misfortunates in his younger years; in any case, he was impelled to travel widely, his peregrinations taking him to a wide swathe of the medieval Ashkenazi world.
And it’s this that makes Rabbi Isaac such an important tradent of Ashkenazi traditions, [i.e.], one who is responsible for preserving and handing on the oral tradition. Isaac Or Zaru’a went everywhere, talked to everyone, and wrote it all down. Isaac sought his first teachers in Prague, [the Bohemian capital], and Regensburg [in nearby Bavaria], . . . and from there to Speyer, possibly Cologne, and Würzburg, followed by Paris and Coucy in France, acquiring teachers in each locale.
This unusually large and broad set of mentors gave Rabbi Isaac grounding in the full array of Ashkenazi learning. From the margins he burst onto the very center of cultural life. The fruit of these many wanderings and years of learning coalesced in Isaac’s magnum opus, the Or Zaru’a. It wasn’t just a belletristic (and comforting) name; Isaac had in him the touch of a poet.
Isaac’s most famous student, Meir of Rothenberg, is perhaps the premier figure in medieval Jewish jurisprudence, whose rulings have an enduring influence on contemporary practice.