(Furqan) 25 : 45
أَلَمْ تَرَ إِلَىٰ رَبِّكَ كَيْفَ مَدَّ الظِّلَّ وَلَوْ شَاءَ لَجَعَلَهُ سَاكِنًا ثُمَّ جَعَلْنَا الشَّمْسَ عَلَيْهِ دَلِيلًا
Didn't you see how your Lord extends the shadow, and if He had wished, He could have made it stationary? Then We made the sun for it an indication.
The extension and contraction of shadows are depending upon the sun’s movement. It is told in verse 36: 40: “And the sun moves toward its destination. That is the determination of the Powerful, the Knower”. See explanation 16: 48-50 and 81.