There have been recent news reports about a piece of papyrus reported to have the Koran on it, and underneath that, a portion of the Bible. I would say— not so fast my friend. Here is one of those reports—- https://www.theguardian.com/books/2018/apr/25/passages-from-the-bible-discovered-behind-quran-manuscript-christies
First of all, what is a palimpsest? It’s a do over. It’s a manuscript that has been used more than once, with a later text written over an earlier one, usually after an erasure of the first one, but modern technology can show us what lies beneath the extant surface text. The manuscript itself purports to be an eight century Islamic manuscript. HOWEVER, the issue is provenance. We do not know where this document that came into the hands of Christie’s auction house came from. And in the light of many forgeries of such texts, for fun and prophet err… profit, one always has to say ‘SHOW ME THE PROVENANCE’. The subtext, if we can call it that is in Coptic, and involves some Biblical material. While I was working at the Museum of the Bible last week Prof. Michael Holmes says that this phenomenon is actually not unprecedented, nor is it improbable. But until we have some sort of clear indication of provenance, where this manuscript came from and when (the age of the papyrus itself tells us nothing), it is right to be skeptical when large claims are made about such documents.