Ricoldo conceded Muslims differed over interpretation but not over divine origin.

Evidence

The fuqaha’, he said, teach that God revealed the Qur’an to Muhammad, and that he wrote it from the mouth of God; but, he went on, the Muslims agree only that it was given by God - totum enim est a nostro Deo - and will never agree about its interpretation.’ — Norman Daniel, Islam and the West, 229