Sleep is presented here as one of Allah’s favours to man and a mercy for the distressed, while Allah Himself is overtaken by neither drowsiness nor sleep. The verses describe it as a form of death, during which Allah takes the souls, and recall that visions come during sleep and that calamities then strike harder.
Verses gathered from a topical index of the Quran, in Mushaf order; every verse is quoted in full.
[Remember, O Muḥammad], when Allāh showed them to you in your dream as few; and if He had shown them to you as many, you [believers] would have lost courage and would have disputed in the matter [of whether to fight], but Allāh saved [you from that]. Indeed, He is Knowing of that within the breasts.
And when he reached with him [the age of] exertion, he said, "O my son, indeed I have seen in a dream that I [must] sacrifice you, so see what you think." He said, "O my father, do as you are commanded. You will find me, if Allāh wills, of the steadfast."