And those who disbelieve say, `Why has not (the whole of) the Qur'ân been revealed to him all at once? (But We have revealed it) in this manner (- piece by piece out of necessity). And (inspite of the fact that it has not been revealed all at once,) We have arranged it in an excellent (form and order of) arrangement (and free of all contradictions) so that We may thereby lend strength to your heart.