أَلَمْ تَرَ إِلَىٰ رَبِّكَ كَيْفَ مَدَّ ٱلظِّلَّ وَلَوْ شَآءَ لَجَعَلَهُۥ سَاكِنًا ثُمَّ جَعَلْنَا ٱلشَّمْسَ عَلَيْهِ دَلِيلًا

Alam tara ila rabbika kayfa madda aththillawalaw shaa lajaAAalahu sakinan thumma jaAAalnaashshamsa AAalayhi daleela

Have you not considered your Lord - how He extends the shadow, and if He willed, He could have made it stationary? Then We made the sun for it an indication.