English grammarian and lexicographer of the late twelfth and early thirteenth centuries. His mother probably was a Jewess named Comitissa, of Cambridge, whence the name "Hanessiah." In his youth he wrote a work (now lost) on Hebrew grammar entitled "Leshon Limmudim"; it 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 Ḳimḥ
The tombstone of a Rabbi Moses, son of Rabbi Isaac, was found at Ludgate, London, in the time of Elizabeth; Stowe, in his "Survey," stated that it came from the Jewish cemetery in Jewin street at the time of the barons' revolt against John in 1215. If this is his tombstone Moses ben Isaac must have died before that date.