It must be constantly remembered that the Qu r’ān is not just descriptive but is primarily prescriptive. Both the content of its message and the power of the form in which it is conveyed are designed not so much to "inform" men in any ordinary sense of the word as to change their character. The psychological impact and the moral import of its statements, therefore, have a primaryrole. Phrases like "God has sealed their hearts, blinded their eyes, deafened them to truth” in the Qur’ān do have a descriptive meaning in terms of the psychological processes described earlier; but even more primarily in such contexts, they have a definite psychological intention: to change the ways of men in the right direction.
Fazlur Rahman, Major Themes of the Qur'an
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