Al-'Ankabut (The Spider)
Surah 29 · Verse 48
And earlier to this, you were not (able) to read from a book nor were you (able) to write it with your right hand. (Had you known reading and writing) then those involved in falsehood would have doubted.
Earlier to the revelation of the Quran Prophet Muhammed (PBH) did not know reading and writing, had he known, then some people would have thought that he was the author of the Quran and not Allah (SWT). This fact itself is a clear sign or proof of the Divine origin of the Quran for people who have knowledge. Only the unjust deny the Divine origin of the Quran, demanding other signs or proofs, which are totally in the control of Allah (SWT) and Who is sufficient as a Witness.
