التفسير التبليغي
(أَلَمْ تَرَوْا كَيْفَ خَلَقَ اللَّهُ سَبْعَ سَمَاوَاتٍ طِبَاقاً)
After He mentioned to them the proof of Tawhid (Oneness of God) from themselves, He followed it with the proof from the horizons, saying: (أَلَمْ تَرَوْا كَيْفَ خَلَقَ اللهُ سَبْعَ سَمَاوَاتٍ طِبَاقًا - Do you not see how Allah has created seven heavens in layers?).
Contemplating the sky and the magnificent creations within it is among the clear proofs and evidences indicating the Oneness of Allah.
Seven heavens in layers, which neither sight nor insight can penetrate, and within them are creations of Allah that none knows or enumerates except Allah.
(أَلَمْ تَرَوْا كَيْفَ خَلَقَ اللهُ سَبْعَ سَمَاوَاتٍ) - He said that in disapproval of their lack of contemplation.
His saying: (سَبْعَ سَمَاوَاتٍ طِبَاقًا) means: some of them are above others.
Source: التفسير التبليغي