Surah Al-Muddaththir, verse 31

وَمَا جَعَلْنَآ أَصْحَـٰبَ ٱلنَّارِ إِلَّا مَلَـٰٓئِكَةً ۙ وَمَا جَعَلْنَا عِدَّتَهُمْ إِلَّا فِتْنَةً لِّلَّذِينَ كَفَرُوا۟ لِيَسْتَيْقِنَ ٱلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ وَيَزْدَادَ ٱلَّذِينَ ءَامَنُوٓا۟ إِيمَـٰنًا ۙ وَلَا يَرْتَابَ ٱلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ وَٱلْمُؤْمِنُونَ ۙ وَلِيَقُولَ ٱلَّذِينَ فِى قُلُوبِهِم مَّرَضٌ وَٱلْكَـٰفِرُونَ مَاذَآ أَرَادَ ٱللَّهُ بِهَـٰذَا مَثَلًا ۚ كَذَٰلِكَ يُضِلُّ ٱللَّهُ مَن يَشَآءُ وَيَهْدِى مَن يَشَآءُ ۚ وَمَا يَعْلَمُ جُنُودَ رَبِّكَ إِلَّا هُوَ ۚ وَمَا هِىَ إِلَّا ذِكْرَىٰ لِلْبَشَرِ ﴿٣١﴾

74:31 We have only appointed angels as keepers of the Fire, and We have only made their number as a test for the disbelievers, so that those who were given the Scripture may have certainty and the believers may increase in faith; and neither those who were given the Scripture nor the believers may have any doubts; and so that those [hypocrites] in whose hearts is sickness and the disbelievers may say, “What does Allah mean by this number?” Thus Allah causes to stray whom He wills and guides whom He wills, and none knows the soldiers of your Lord but He. This is but a reminder to mankind