Surah Al-Hijr Verse 8

مَا نُنَزِّلُ الْمَلَائِكَةَ إِلَّا بِالْحَقِّ وَمَا كَانُوا إِذًا مُنْظَرِينَ

We do not send down the angels except with truth; and the disbelievers would not then be reprieved