3:191
ٱلَّذِينَ يَذْكُرُونَ ٱللَّهَ قِيَٰمًۭا وَقُعُودًۭا وَعَلَىٰ جُنُوبِهِمْ وَيَتَفَكَّرُونَ فِى خَلْقِ ٱلسَّمَٰوَٰتِ وَٱلْأَرْضِ رَبَّنَا مَا خَلَقْتَ هَٰذَا بَٰطِلًۭا سُبْحَٰنَكَ فَقِنَا عَذَابَ ٱلنَّارِ
Who remember Allah while standing or sitting or [lying] on their sides and give thought to the creation of the heavens and the earth, [saying], "Our Lord, You did not create this aimlessly; exalted are You [above such a thing]; then protect us from the punishment of the Fire.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
The Proofs of Tawhid for People of Understanding, their Characteristics, Speech, and Supplications
Allah said,
إِنَّ فِى خَلْقِ السَّمَـوَتِ وَالاٌّرْضِ
(Verily, in the creation of the heavens and the Earth,) 3:190, referring to the sky in its height and spaciousness, the earth in its expanse and density, the tremendous features they have of rotating planets, seas, mountains, deserts, trees, plants, fruits, animals, metals and various beneficial colors, scents, tastes and elements.
وَاخْتِلَـفِ اللَّيْلِ وَالنَّهَارِ
(And in the alternation of night and day), as one follows and takes from the length of the other. For instance, at times one of them becomes longer than the other, shorter than the other at times and equal to the other at other times, and the same is repeated again and again, and all this occurs by the decision of the Almighty, Most Wise. This is why Allah said,