Tafsir of Fussilat 41:37

(And of His signs) which indicate His majestic affairs—glorified be His status—(are the night and the day) in their occurrence, their alternation, and the insertion of each into the other; (and the sun and the moon) in their illumination, their disparity in intensity of light, size, and movements, for example.

The night was mentioned first, it is said, to alert to its precedence, even though darkness is a non-existence. Mentioning the sun after the day is appropriate because it is the day’s sign and the cause of its illumination, and because it is the source of the moon’s light, based on what they have said: that it is derived from the radiance of the sun. As for the sun’s radiance, the well-known view is that it is not something incidental to it from another celestial body; some have said it is from the Throne. Philosophers today conjecture that it is from another body, claiming they see a slight darkness at the edge of the sun.

(Do not prostrate to the sun nor to the moon) for they are among the sum of His creatures—sublime and exalted is He—subjugated according to His will, just as you are. (But prostrate to Allah who created them). It is said that the pronoun refers to the four things mentioned. The intention is to attach the action to the sun and the moon, but the night and the day were organized alongside them as an indication that they are among the number of things that have no intellect or volition, since the night and the day are necessarily so. Had the pronoun been in the dual form, it would not have provided such an indication.

A group has ruled that non-rational entities are treated according to the rule of the feminine, as Al-Zamakhshari has stated; thus one says: "The pens (al-aqlam), I sharpened them (baraytuha) and I sharpened them (baraytuhunna)." One should not imagine that because the pronoun refers to the night, day, sun, and moon, the masculine gender should be given precedence. The answer is that since they are all "signs," they are counted as feminine—an explanation that is dispensed with by the aforementioned rule. Yes, Abu Hayyan said: A distinction should be made between the plural of paucity and the plural of abundance; for the former, the most eloquent form is to use the singular feminine pronoun, as in "the trunks (al-ajdha') broke (inkasarat)" according to the most eloquent usage, while for the latter, the most eloquent form is the feminine plural, as in "the trunks (al-judhu') broke (inkasarna)." What is in the verse is not a plural of paucity in a single word, but it is treated as though it were expressed as such. It is also said that the pronoun refers to the sun and the moon, and the dual is treated as a plural, and the plural of non-rational beings is made feminine. Since one says "suns (shumus)" and "moons (aqmar)" due to their variation by days and nights, it is permissible for the pronoun to return to them in the plural. It is also said that the pronoun refers to the "signs" previously mentioned in His saying, (And of His signs).

(If it is Him you worship). Since prostration is the highest degree of worship, it must be reserved for Him—the Exalted and Majestic. Ali—may Allah ennoble his countenance—and Ibn Mas’ud used to prostrate at (you worship). The opinion that this is the place of prostration is attributed to Al-Shafi’i. Ibn Abbas, Ibn Umar, Abu Wa’il, Bakr bin Abdullah, and likewise it is reported from Ibn Wahb, Masruq, Al-Sulami, Al-Nakha’i, Abu Salih, Ibn Wathab, Al-Hasan, Ibn Sirin, and Abu Hanifah—may Allah be pleased with them all—prostrated at (they do not weary). In Al-Tahrir, it is reported from Al-Shafi’i—may Allah be pleased with him—and in Al-Kashf, the most correct of the two opinions among our scholars—meaning the Shafi’is—is that the place of prostration is (they do not weary), which is also the school of Imam Abu Hanifah. The rationale is that it completes the meaning, following the style of "prostrate," for arrogance regarding it is blameworthy. Some have attributed this to precaution: if it were at (you worship), postponement is permissible due to the shortness of the interval, but if it were at (they do not weary), haste is not permissible.