Tafsir Al-Jalalayn: Al-A'raaf, Ayah 54

Surely your Lord is God Who created the heavens and the earth in six days of the days of this world that is to say in the equivalent thereof since there was no sun then. Had He willed He could have created them in an instant; but the reason for His not having done so is that He wanted to teach His creatures to be circumspect; then presided upon the Throne a presiding befitting of Him al-‘arsh ‘throne’ in the classical language is the elevated seat on which a king sits. He cloaks read yughshī or yughashshī the night with the day that is He covers each one with the other each following the other in swift pursuit — and the sun and the moon and the stars if all of these are read in the accusative then they constitute a supplement to al-samāwāt ‘the heavens’ and if in the nominative then they constitute the subject of the sentence the predicate of which follows have been made subservient have been subdued by His command by His power. Verily His is all creation and the command in its entirety. Blessed Magnified be God the Lord the Master of the Worlds!