Al-Muddaththir 74:31

Wama jaAAalna as-habaannari illa mala-ikatan wamajaAAalna AAiddatahum illa fitnatan lillatheenakafaroo liyastayqina allatheena ootoo alkitabawayazdada allatheena amanoo eemananwala yartaba allatheena ootoo alkitabawalmu/minoona waliyaqoola allatheena feequloobihim maradun walkafiroona mathaarada Allahu bihatha mathalan kathalikayudillu Allahu man yashao wayahdee man yashaowama yaAAlamu junooda rabbika illa huwa wamahiya illa thikra lilbashar

And We have not made the keepers of the Fire except angels. And We have not made their number except as a trial for those who disbelieve - that those who were given the Scripture will be convinced and those who have believed will increase in faith and those who were given the Scripture and the believers will not doubt and that those in whose hearts is disease [i.e., hypocrisy] and the disbelievers will say, "What does Allāh intend by this as an example?" Thus does Allāh send astray whom He wills and guide whom He wills. And none knows the soldiers of your Lord except Him. And it [i.e., mention of the Fire] is not but a reminder to humanity.

And We did not make wardens of the Fire but (from) angels, and did not fix their number but as a test for those who disbelieve, so that those who are given the Book may come to believe, and those who believe may improve in belief, and so that those who are given the Book and those who believe may not doubt (its correctness), and so that those having malady in their hearts and the disbelievers say, “What has Allah meant by this strange statement?” Thus Allah lets go astray whomever He wills, and leads to the right path whomever He wills. And no one knows the hosts of your Lord but He. And this is nothing else but a reminder for mankind.