Have you not seen how your Lord spread the shadow. If He willed, He could have made it still - But We have made the sun its guide (i.e. after the sunrise, the shadow shrinks and vanishes at midnoon and then again appears in the afternoon with the decline of the sun, and had there been no sunlight, there would have been no shadow).

Have you not seen how your Lord extends the shade—He could have simply made it ˹remain˺ still if He so willed—then We make the sun its guide,