Background
His mother probably was a Jewess knicknamed Comitissa of Cambridge.
His mother probably was a Jewess knicknamed Comitissa of Cambridge.
In his youth he wrote a work (now lost) on Hebrew grammar entitled Leshon Limmudim. lieutenant is referred to in his Sefer ha-Shoham, or "Onyx Book," the title of which is an anagram of his name. The latter work (part of which was published at Oxford in 1882) shows some knowledge of Arabic and of the works of Joseph Kimhi.
The tombstone of a Rabbi Moses, son of Rabbi Isaac, was found at Ludgate, London, in the time of Elizabeth.
John Stow, in his "Survey of London" stated that it came from the Jewish cemetery in Jewin Street at the time of the barons" revolt against King John in 1215. If this is his tombstone Moses ben Isaac must have died before that date.