The Qur’ān (Arabic: القرآن al-qur'ān, literally "the recitation"; also sometimes transliterated as Quran, Koran, or Al-Qur'an) is the central religious text of Islam. Muslims believe the Qur'an to be the book of divine guidance and direction for mankind and consider the text in its original Arabic to be the literal word of Allah, revealed to Muhammad by the Archangel Gabriel over a period of 23 years and view the Qur'an as God's final revelation to humanity.
When Christian and Muslim delegations presented their religions' cases to Khan Telerikh of the Bulgars, the former presented a Bible while the latter presented a Qu'ran. The Khan noticed that the Bible contained illustrations of the stories within, while the Qu'ran did not. Jalal ad-Din explained that Allah has forbidden depictions of living things since the days of the Old Testament, and pointed to the Christians' custom of ignoring this, as an example of their hypocritical picking and choosing within holy writ.