Being interested in the origins of Islam, a very unique document comes to light. It is a 7th Century Christian polemic against Judaism called the Doctrina Jacobi. Since this document was written around 634 AD, this gives us some interesting information about Islamic origins. The document has an interesting passage. This passage reads:
When the candidatus was killed by the Saracens, I was at Caesarea and I set off by boat to Sykamina. People were saying “the candidatus has been killed,” and we Jews were overjoyed. And they were saying that the prophet had appeared, coming with the Saracens, and that he was proclaiming the advent of the anointed one, the Christ who was to come. I, having arrived at Sykamina, stopped by a certain old man well-versed in scriptures, and I said to him: “What can you tell me about the prophet who has appeared with the Saracens?” He replied, groaning deeply: “He is false, for the prophets do not come armed with a sword. Truly they are works of anarchy being committed today and I fear that the first Christ to come, whom the Christians worship, was the one sent by God and we instead are preparing to receive the Antichrist. Indeed, Isaiah said that the Jews would retain a perverted and hardened heart until all the earth should be devastated. But you go, master Abraham, and find out about the prophet who has appeared.” So I, Abraham, inquired and heard from those who had met him that there was no truth to be found in the so-called prophet, only the shedding of men’s blood. He says also that he has the keys of paradise, which is incredible.
This is an interesting passage. It seems that the prophet leading the invasions is still alive. According to the orthodox narrative, Muhammad died in 632 AD and never had any military campaigns outside of Arabia. However, this problem is small. If the Muslims got the date of Muhammad’s death wrong by a couple years, it would not invalidate Islam.
It seems to indicate that the author went to investigate whether this Prophet is truly from God. He mentions about how he interacted with people who had talked with this Prophet. These were not followers of the Prophet. It seems that this man who claims to be a Prophet interacted with the some Christians and Jews who lived in Palestine. The author met with some of them and concluded then that this Prophet it false.
Can we retrieve any doctrine from this small passage? Yes. The passage says: “he was proclaiming the advent of the anointed one, the Christ who was to come.” This is not part of Islamic theology. According to Islam, Jesus Christ is the Messiah(Hebrew for anointed one) and he came 600 years earlier. This is completely inconsistent with traditional Islamic origins. It is also interesting that this Prophet is said to posses the “keys of paradise” which is a phrase found nowhere in Islamic literature. The closest would be the keys that were given to Peter in Matthew 16.
This document is a double-edged sword for Islam. It shows evidence of Arab armies, a new Prophet and a new religion. However, this new religion looks very different than what the Quran and Hadith present.