Muslim dating quran
Allah says in the Quran: The preservation of the Quran has been mainly through oral preservation.
So for a manuscript that dates back to an age near the real age, it may be considered as auxiliary evidence, but it cannot be sufficient evidence as the source of this manuscript must be known. Here comes the importance of the Isnad (chain of narrators), which is to detect the transmission and make sure that no weak points are present within the transmission.
And if you fear poverty, ALLAH will enrich you out of HIS bounty, if HE pleases. Fight those from among the people of the Book, who believe not in ALLAH, nor in the Last Day, nor hold as unlawful what ALLAH and HIS Messenger have declared to be unlawful, nor follow the true religion, until they pay the tax considering it a favour and acknowledge their subjection.
And the Jews say, Ezra is the son of ALLAH, and the Christians say, the Messiah is the son of ALLAH; that is what they say with their mouths. They have taken their priest and their monks for lords besides ALLAH. And they were not commanded but to worship the One God. Holy is HE far above what they associate (yushrikoona) with Him!
Here we shall see how both ways of preservation occurred.
Manuscripts cannot be a sufficient evidence for any source even if its age lies to an age near that supposed for a source, yes it may be considered evidence in usual historical events, or things which are not very critical.