Al-A'raf 7:203–206

And when you do not bring them, that is, the people of Mecca, a sign, from among those which they request, they say, ‘Why have you not chosen one?’, [why have you not] produced one [all by] yourself? Say, to them: ‘I follow only that which is revealed to me from my Lord, and it is not for me to bring anything from myself; this, Qur’ān, is insight, proofs, from your Lord, and a guidance and a mercy for a people who believe’.

And when the Qur’ān is recited, listen to it and pay heed, [refraining] from speech, so that you might find mercy: this was revealed regarding [the requirement of] refraining from speech during the [mosque] sermon, which here has been expressed by [the recital of] ‘the Qur’ān’, because it [the sermon] comprises it; others say that it was revealed regarding the [requirement of silence and attention during the] recitation of the Qur’ān in general.

And remember your Lord within yourself, that is, secretly, humbly, submissively, and fearfully, in awe of Him, and, louder than [speaking] in secret, more quietly than speaking out loud, that is, a middle way between the two, at morning and evening, at the beginning of the day and at its end. And do not be among the heedless, of God’s remembrance.

Surely those who are with your Lord, namely, the angels, are not too proud, they do [not] disdain, to worship Him; they glorify Him, exalting Him as being transcendent above what does not befit Him, and to Him they prostrate, that is, they devote their submission and worship exclusively to Him: so be like them!