Myrna,
I am thinking whether this Rabbi could have been among the select number of Jєωs who know the arcane teachings of Israël, and whether he perhaps adopted the messianic name of Jesus from these teachings. Michel Drach, a famous 19th century Rabbi who converted to the true Religion, has written elaborately on these arcane teachings which prove very clearly that Our Lord Jesus Christ is the promised Messiah. For example, these secret teachings say that the Messiah is the "Son of David" and the "Son of Joseph". He said that the ancient Israelites believed that in the Christ, the Divine Essence would be united with human nature, and that He would be born from the Royal Virgin from Davidic Lineage.
Unto these days, these secret teachings have been transmitted from generation to generation among the Jєωs, but only a select number of them have received these instructions, and they are transmitted exclusively by verbal tradition. They do not write them down.