Tafsir of Al-Furqan 25:45

{Have you not seen your Lord} Have you not looked at the handiwork of your Lord and His power?

{How He extended the shadow} The meaning of "extending" the shadow is that He caused it to stretch and spread so that people might benefit from it.

{And if He had willed, He could have made it stationary} Meaning: clinging to the base of whatever casts a shadow—be it a mountain, a building, or a tree—without spreading, such that no one could benefit from it. The spreading and extension of the shadow are termed "movement," while the absence of this is termed "stillness."

{Then We made the sun a guide for it} The meaning of the sun being a "guide" is that people use the sun and its states during its course to determine the states of the shadow—whether it is fixed in a place or receding, expanding or contracting—and thus they arrange their need for the shadow or their independence from it accordingly.

{Then We withdraw it to Ourselves, a gradual withdrawal} Meaning: He abrogates it with the sunlight. {Gradual} means slowly and at leisure. In this gradual withdrawal, bit by bit, there are benefits that cannot be counted or enumerated. If it were withdrawn all at once, most of the benefits people derive from both the shadow and the sun would be disrupted.

If you ask: What is the position of the word "then" (thumma) in these two instances? I say: Its position is to clarify the gradation of the three matters. The second is greater than the first, and the third is greater than both, likening the distance between them in excellence to the distance between events in time.

Another interpretation: He extended the shadow when He built the sky like a pitched dome and spread the earth beneath it. The dome cast its shadow upon the earth, and we would be in its expanse, shielded from the light. Had He willed, He could have made it stationary, fixed in that state. Then, He created the sun and made it a guide for that shadow—meaning He empowered it over the shadow and set it up as a guide to be followed, just as a guide is followed on a path. Through the sun, the shadow increases and decreases, extends and contracts. Then, He abrogated it with the sun, withdrawing it with an easy, gradual withdrawal, not a difficult one.

It is also possible that it means: withdrawing it at the onset of the Hour by withdrawing its causes—the physical bodies that cast the shadow. Thus, He has mentioned its annihilation by the annihilation of its causes, just as He mentioned its creation by the creation of its causes. His saying, {We withdraw it to Ourselves}, points to this, as does His saying {gradual}, just as He said: {That is a gathering easy for Us} (Qaf: 44).

{And it is He who made the night for you as a garment, and sleep as a rest, and made the day a resurrection.}