Quran 72:8 from Surah Al-Jinn on Divine Marvels.
وَأَنَّا لَمَسۡنَا ٱلسَّمَآءَ فَوَجَدۡنَٰهَا مُلِئَتۡ حَرَسٗا شَدِيدٗا وَشُهُبٗا
English translation: And that we sought to touch the heaven but we found it filled (with) guards severe and flaming fires
Transliteration: wa-anna lamasna al-samaa fawajadnaha muli-at harasan shadidan washuhuban