Quran 72:8

وَأَنَّا لَمَسْنَا السَّمَاءَ فَوَجَدْنَاهَا مُلِئَتْ حَرَسًا شَدِيدًا وَشُهُبًا

'And we pried into the secrets of heaven; but we found it filled with stern guards and flaming fires.