Moses ben Joseph ben Merwan ha-Levi (Also known as Moses Halavi or ha-Lawi or simply, Allawi[1]) flourished about the mid-12th century[2] and was a prominent Provençal rabbi, philosopher, and talmudist.
His colleagues addressed him as "Great scholar, Nasi Rabbi Moses," and his ritual decisions and Talmudic comments are often quoted.
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, and Joseph Albo (all of whom quote him).
If this identification is correct, Moses was one of the foremost cabalists of southern France, as Jacob's words in the passage cited indicate.