However, mainstream Islamic tradition holds that Muhammad was not Jewish. His parents are described in most Sunni sources as pagans, though some Shiite sources suggest they were monotheists belonging to the hanifs, a group of pre-Islamic Arabs who followed a form of monotheism. According to Islamic belief, Muhammad was a Hanif—a follower of the religion of Abraham—distinct from both Judaism and Christianity. He is considered the final prophet in a line that includes Moses and Jesus, but not a Jew in the religious or ethnic sense.

Jewish views on Muhammad are varied. While many medieval Jewish texts, such as those by Maimonides, refer to Muhammad as a "madman" and a false prophet, some later Jewish thinkers, like Natan’el al-Fayyumi, acknowledged him as a true prophet sent to the Arabs, though not to the Jews. The apocalyptic Midrash The Secrets of Rabbi Simon ben Yohai even compares Muhammad to the Jewish Messiah in some interpretations. Nevertheless, the majority of Jewish tradition rejects Muhammad’s prophethood, viewing his teachings as incompatible with the Torah, particularly due to perceived contradictions, such as the permissibility of eating camel meat, which is prohibited in Jewish law.

Genetic studies have shown that the Quraysh tribe, to which Muhammad belonged, shares a lineage with the Jewish Cohen modal haplogroup, suggesting a possible ancient genetic link between the Quraysh and Jewish populations. However, this does not confirm religious or ethnic Jewish identity, as genetic ancestry does not equate to religious affiliation.

In conclusion, while there are claims and some historical and genetic evidence suggesting Jewish ancestry or cultural influence in Muhammad’s life, the prevailing religious and scholarly consensus—both within Islam and mainstream Judaism—does not support the idea that Muhammad was Jewish in a religious or ethnic sense. The theory remains a fringe interpretation with limited academic and theological acceptance."

(http://www.autoadmit.com/thread.php?thread_id=5788001&forum_id=2/#49361563)