The meaning of this word is disputed among the scholars. It is used in varying contexts in the Qur'an itself, and can hardly mean the same thing in all places. In the context of debates, Muslims like to emphasize the meaning "criterion" and claim on this basis that the Qur'an is the criterion to decide between right and wrong (genuine and corrupted) in the Jewish and Christian Scriptures. However, furqaan is never used in this way in the Qur'an, and it is obviously fallacious to build any argument on a word whose meaning is not clear itself.

One of the likely sources of the word is the Syriac purqaana which means salvation.