@Zaotar
Kinda off topic but do you know anything about the inclusion of the Christian Legend about Alexander being included in the Quran? Is this a passage that was added later because the Legend was written as a piece of Byzantine propaganda in 629. The two stories have identical elements to them and it seems nearly certain that one influenced the other and as Muhammad's Quran would not have been widely known enough to influence Christian propaganda written in the heart of Byzantium it would seem the Quran borrowed from the legend.
In my view it's dead certain that the Qur'an is referring to the Syriac text, and also that the Qur'an presumes that its audience is already familiar with and already knows that specific story. What's particularly interesting (as you probably know) is how the Syriac text explains so many otherwise baffling aspects of the Qur'an's version of the story.
There is a phenomenal essay on this subject by Kevin van Bladel in the book "The Qur'an in its Historical Context." I believe you can find a free pdf on the Internet, or rent it for cheap on a Kindle. It is a powerhouse demonstration of how badly traditional Muslims have misread the Qur'an by interpreting it as a pagan artifact, rather than a product of literate Northern Judaeo-Christian society, particularly *Syriac* language and culture.
This obviously has numerous implications, including (a) though it is in an Arabic dialect(s), the Qur'an was produced in a literate environment that was highly familiar with Syriac written texts from the orthodox Syriac tradition; (b) given the late composition of this text, the sections of the Qur'an referring to this story were likely written after Mohammed's death, or, alternatively, traditional Muslim chronology is wrong about the date of his death (both are equally likely explanations in my view). Van Bladel argues that the Syriac text must have been distributed widely and quickly so that it reached Mecca and Medina very fast, but the more sensible explanation is that this portion of the Qur'an is not "Meccan/Medinan" at all.
Btw, I can't resist quoting part of that article, because it always irritates me when people think of Mohammed's followers as following a radically different religion from Christianity. People forget that Christianity and early Islam in this time period, in my view, had a virtually identical message about the impending apocalypse (which, after all, is EXACTLY WHAT THE QUR'AN SAYS OVER AND OVER, and yet which people inexplicably ignore .... just amazing). At any rate, here's the quote:
"It is often over-looked that Jesus was thought even by Christians to be prophesying nothing less than the end of the world (as in Matthew 24 and Luke 21:5–28), and that this would be preceded by a siege of Jerusalem (Luke 21:20). The sack of Jerusalem by the Persians in 614 therefore shocked Christian contemporaries especially because it seemed to indicate that the end the world and the return of the Messiah were near according to the very words of Jesus. Other signs predicted by Jesus preceding the end would be seen in the heavens, and there would be “distress of nations confused by the roaring of the sea and the waves” (Luke 21:25). Contemporary sources show that witnesses to the great war of 603–30 saw the fulfillment of Jesus’ words in it."
This is the regional context in which Mohammed emerged, an expectation of imminent judgment and bodily resurrection of the dead in connection with the Messiah's return. This is the religion he preached. It is the religious view expressed in the Alexander Legend. It was almost identical to the religion of Christianity more generally, and could be summarized as sort of a monotheistic consensus view in the region. This fundamental identity is often missed by people who see Christianity and Islam through the vast apparatus that was slowly overlaid on their original texts. Ironic that Mohammed himself was making that exact point re Christianity (that Jesus was just a messenger bringing this message of divine imminent judgment and resurrection), and then almost the exact same thing happened to his preaching.