He was a nephew and pupil of
Isaac ben Merwan ha-Levi. His colleagues addressed him as "Great scholar, Nasi Rabbi Moses," and his ritual decisions and Talmudic comments are often quoted. He directed the
yeshiva at
Narbonne, and several of his pupils subsequently achieved fame.
Abraham ben David and
Zerachiah ha-Levi of Girona were among his pupils. He was in continuous correspondence with his younger colleague
Abraham ben Isaac of Narbonne, the
av bet din, who was his pupil and who, by preference, sought Moses' advice in difficult casuistic questions. He was well regarded by several rabbis, such as
Isaac Abarbanel,
Hasdai Crescas,
Joseph Albo, and Joseph Ibn Waqar (all of whom quote him). Jacob ben Moses of Bagnols quotes a document relating to a divorce drawn up at Narbonne in 1134 and signed by the "great rabbi Moses ben Joseph and by Eliezer ben Zechariah. "Gross identifies Moses ben Joseph with Moses ben Joseph ben Merwan ha-Levi. If this identification is correct, Moses was one of the foremost cabalists of southern France, as Jacob's words in the passage cited indicate. However, Moses is not otherwise known as a mystic. == Works ==