I want to begin by saying that I hope there is no animosity between us, since these kinds of discussions can get heated.
Is there in the Didascaly an attestation/report of muhajirun?; Therefore, it is perfectly normal/possible that a non Muslim (the Didascaly) in good faith believes that there was a "prophet" alive and kicking because of the events somewhere. Perfectly possible. Therefore the Didascaly is not an attestation from the muhajirun themselves about Muhammad alive and kicking; I was talking about the muhajirun, not the Didascaly.
Your assessment of the
Didascaly is, in my humble opinion, mistaken, and not based on a detailed reading of the actual text, nor the scholarly commentary on it.
Abraham’s source of information was based on interviews he had conducted, and this is very important, with “those who had
met him [that is, Muhammad].” He had
met and
spoken with the Saracens.
The text reports that Muḥammad was preaching the return of Jesus. Furthermore, its indication that Muḥammad was alive is descriptive and consistent with the testimony of other sources. This information could have been known to Abraham’s informants, “who had
met him”. And this quite explicit, since it says that Muḥammad came “
with the Saracens”.
Now unto your other questions.
What the Didascaly brings as new information about the "prophet" which precede and could validate those (Muslims sources) of the 8 and 9 c.?
Good question. I can think of three things: Muḥammad existing, that he preached the return of Jesus, and that he possessed the Keys to Paradise. All consistent with the later Arabic sources.
The Didascaly do not EVEN know the NAME of the prophet.
No worries. He is first mentioned by name in 637 CE. That is around the same time. We can also be sure that the
Didascaly also refers to the same person.
What the Didascaly brings as new information about the "prophet" that we did not know already by other non Muslims sources?
Not sure of the significance of this point you are raising. The
Didascaly being the earliest we possess, I do not know it should bring new information not found in slightly later sources. Anyways, your other questions made more sense.
You defend the traditional account: you speak about a "prophet", and you brings hadith .... So, either you have a problem with your own mind, which do not comprehend what he does and how it works, either...
My belief that there existed a prophet based on the actual evidence is not me supporting the traditional account. Same thing applies to the hadith. I relied on methods employed in modern Hadith Studies in order to date a certain tradition back to a Companion of Muhammad. I did not assume the reliability of all hadith. Speaking of hadith, I must say this in the name of intellectual honesty. I made a mistake. The actual common link of “A Bequest May Not Exceed One-Third” tradition is not Saʿd ibn Abī Waqqās, but rather, the Meccan ʿAbd Allāh b. Khuthaym (d. 136/753 or 144/761–2).
Be that as it may, in light of Lawrence Conrad's great work, we can be reasonably sure that there existed genuine common links in the generation of the Companions. That is a possibility we must contend with.
The above paragraph can also be a response to your lengthy quotation from Marijin van Putten. There is more to be said. A group of scholars have manged to date a corpus of traditions back to the early Successor ʿUrwa ibn al-Zubayr. This is significant. ʿUrwa was the nephew of ʿĀʾishah, and the brother of ʿAbd Allāh ibn al-Zubayr, whom we know existed. ʿUrwa’s proximity to the actual events he reports stand in the favour of minimal historicity. His transmission is also very immediate and uncomplicated, the only one standing between him and Muḥammad being his aunt, ʿĀʾishah. His source(s) is thus an eyewitness. And you know what? Motzki, the man who developed the isnād-cum-matn analysis and the one Marijin responded to, agrees with dating these traditions back to ʿUrwa.
Marijin’s comments is certainly true, in that it applies to many tradition, but not all. And that is the key distinction. I do not know if he has engaged with ʿUrwa’s corpus.
I might have missed something, but I think I responded to all your objections, or at least tried to.