Qur'an 67:3

ٱلَّذِى خَلَقَ سَبْعَ سَمَـٰوَٰتٍ طِبَاقًا ۖ مَّا تَرَىٰ فِى خَلْقِ ٱلرَّحْمَـٰنِ مِن تَفَـٰوُتٍ ۖ فَٱرْجِعِ ٱلْبَصَرَ هَلْ تَرَىٰ مِن فُطُورٍ

“[And] who created seven heavens in layers. You do not see in the creation of the Most Merciful any inconsistency. So return [your] vision [to the sky]; do you see any breaks?”

Al-Mulk 67:3 · Saheeh International