On the Quran

You claim that the evidentiary miracle is present and available, namely, the Koran. You say: “Whoever denies it, let him produce a similar one.” Indeed, we shall produce a thousand similar, from the works of rhetoricians, eloquent speakers and valiant poets, which are more appropriately phrased and state the issues more succinctly. They convey the meaning better and their rhymed prose is in better meter. … By God what you say astonishes us! You are talking about a work which recounts ancient myths, and which at the same time is full of contradictions and does not contain any useful information or explanation. Then you say: “Produce something like it?!

by Abū Bakr Muhammad ibn Zakariyā al-Razi