Surah Al-Furqan 25:45

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

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.

Translation: Saheeh International

Tafsir

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. …

Excerpt from Tafsir al-Jalalayn, commentary on 25:45, via Quran.com. The reader has the full commentary and 9 more tafsirs.