"The Quran, like other sacred scriptures, associates knowledge and understanding with the heart, and the blindness of the heart with loss of understanding, as for example when God, after complaining of man’s not learning the appropriate lessons from earlier sacred history, asserts, “For indeed it is not the eyes that grow blind, but it is the hearts, which are within the bosoms, that grow blind” (22:46). This blindness of the heart so characteristic of fallen man is also described by the Quran as a hardening of the heart. “But their hearts were hardened, and the devil made all that they used to do seem fair unto them!” (6:43). Also, ““Woe unto those whose hearts are hardened against remembrance of Allah. Such are in plain error” (39:22). Furthermore, the Quran identifies this hardening of the heart with a veil that God has cast over the heart of those who have turned away from the truth. “We have placed upon their hearts veils, lest they should understand, and in their ears a deafness” (6:25); also, “And We place upon their hearts veils lest they should understand it, and in their ears a deafness” (17:46)."