Al-Muddaththir 74:31

وَمَا جَعَلْنَا أَصْحَابَ النَّارِ إِلَّا مَلَائِكَةً ۙ وَمَا جَعَلْنَا عِدَّتَهُمْ إِلَّا فِتْنَةً لِّلَّذِينَ كَفَرُوا لِيَسْتَيْقِنَ الَّذِينَ أُوتُوا الْكِتَابَ وَيَزْدَادَ الَّذِينَ آمَنُوا إِيمَانًا ۙ وَلَا يَرْتَابَ الَّذِينَ أُوتُوا الْكِتَابَ وَالْمُؤْمِنُونَ ۙ وَلِيَقُولَ الَّذِينَ فِي قُلُوبِهِم مَّرَضٌ وَالْكَافِرُونَ مَاذَا أَرَادَ اللَّهُ بِهَـٰذَا مَثَلًا ۚ كَذَٰلِكَ يُضِلُّ اللَّهُ مَن يَشَاءُ وَيَهْدِي مَن يَشَاءُ ۚ وَمَا يَعْلَمُ جُنُودَ رَبِّكَ إِلَّا هُوَ ۚ وَمَا هِيَ إِلَّا ذِكْرَىٰ لِلْبَشَرِ

wa-ma ja'alna ashab an-nar illa mala'ikah wa-ma ja'alna 'iddatahum illa fitnah lil-ladhina kafaru li-yastayqin al-ladhina utu al-kitab wa-yazdad al-ladhina amanu iman wa-la yartab al-ladhina utu al-kitab wal-mu'minun wa-liyaqul al-ladhina fi qulubihim marad wal-kafirun madha arada Allah bihadha mathalan kadhalika yudillu Allah man yasha' wa-yahdi man yasha' wa-ma ya'lam junud rabbak illa huwa wa-ma hiya illa dhikra lil-bashar

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 hypocrisy and the disbelievers will say, "What does Allah intend by this as an example?" Thus does Allah leave astray whom He wills and guides whom He wills. And none knows the soldiers of your Lord except Him. And mention of the Fire is not but a reminder to humanity.

Saheeh International translation