Tafsir of Al-Jathiyah 45:27

This is a statement of absolute exclusivity and total authority over them and everything between them. It comes after His statement regarding His authority—Exalted and Majestic is He—concerning the giving of life, the causing of death, the resurrection, and the gathering for the purpose of requital. It is, therefore, a generalization of [His] power after [its] specification.

Al-Zamakhshari said: The operative [verb] for "the Day the Hour is established" is "will lose," and "that Day" is a substitute (badal) for "the Day the Hour is established." Ibn Atiyyah related this from a group. The advancement of the adverbial phrase before the verb is for restriction, because every loss at the time of that loss on that Day is as if it were no loss at all. It also observes the rhythm of the verse-endings, as is said.

The theory of substitution has been challenged on the basis that the tanwin in "that Day" (yawma'idhin) is a substitute for the sentence to which it is annexed. It is apparent that this sentence is understood by the context of what precedes it—namely, "the Hour is established"—so it is said: "And the Day the Hour is established, on the day [the Hour is established], the falsifiers will lose." Thus, it is an emphasis (ta'kid), not a substitute, since there is no basis for substitution. For this reason, it was said: It is more akin to emphasis. Abu Hayyan’s statement—that if it is a substitute, it is rare and permissible, otherwise it is not—neither satisfies nor nourishes.

Some have labored and claimed that the second "Day" signifies the time which is a part of the day the Hour is established, making it a "partial substitute" (badal ba'd) containing an implied referent. Since the manifestation of their loss is in that [Day], it is the intended [meaning] in relation to it.

A faction said: The operative for "the Day the Hour is established" is that which the "dominion" implies. They said: This is because the Day of Resurrection is a third entity, not of the heavens or the earth, such that it could be manifest to them. It is as if it were said: "And to Allah belongs the dominion of the heavens and the earth on the Day the Hour is established." In this case, "that Day" is governed by the verb "will lose," and the sentence is an initiation (isti'naf), even if it has a connection to what precedes it by way of the compensatory tanwin.

It is also said: It is permissible that it be a conjunction for an adverbial phrase governed by the aforementioned "dominion," as if it were said: "To Allah belongs the dominion of the heavens and the earth today, and on the Day the Hour is established." But this is as you see it [to be weak].

The "falsifiers" (al-mubtilun) are those who enter into falsehood. Perhaps what is intended by it is the greatest of its types, which is disbelief.