﴿ أَلَمْ تَرَ إِلَىٰ رَبِّكَ كَيْفَ مَدَّ ٱلظِّلَّ وَلَوْ شَآءَ لَجَعَلَهُۥ سَاكِنًۭا ثُمَّ جَعَلْنَا ٱلشَّمْسَ عَلَيْهِ دَلِيلًۭا ﴾

“Art thou not aware of thy Sustainer [through His works]? - how He causes the shadow to lengthen [towards the night] when, had He so willed, He could indeed have made it stand still: but then, We have made the sun its guide;”

Have you not seen contemplated the work of your Lord how He extends the twilight shadow? from the point of daybreak to the point of sunrise. For had He your Lord willed He would have made it still ever-present so that it does not disappear with the rising of the sun. Then We made the sun an indicator of it of the shadow; were it not for the sun the shadow would not have been known.