Tafsir of Al-Mursalat 77:12

{To which Day has it been postponed?}

It is said that this is the object of an implied verb of saying, which acts as the answer to "when" (idha). That is, it is said, "To which Day... etc."

Postponement (ta’jil) is understood in the sense of delaying, as in their saying "a deferred debt" (dayn mu’ajjal) in contrast to one that is immediate. The pronoun refers to what the context implies, and the interrogation is for the purpose of magnification and expressing wonder at the terror of that Day. That is: when such and such occurs, it is said, "To which Day have the matters pertaining to the Messengers been delayed?"—such as the punishing and humiliating of the disbelievers, the blessing and honoring of the believers, and the manifestation of what the Messengers (peace be upon them) used to mention regarding the Afterlife and its conditions, or the atrocity of its affairs and its terrors.

It is permissible for the pronoun to refer to the matters indicated beforehand: the blotting out of the stars, the cleaving of the sky, the scattering of the mountains, and the timing of the Messengers. It may also refer to the Messengers themselves, though the meaning remains similar to what has preceded.

It is also said that the implied statement is in the position of a state (hal) from the nominative pronoun in "were timed" (uqti-tat); that is, "it being said at that time: To which Day has it been postponed?" Alternatively, the sentence itself, without an implied statement, could be in the position of the second object of "were timed," assuming it carries the meaning of "were informed." It would be as if it were said: "And when the Messengers were informed of the time of their postponement"—that is, of its arrival and occurrence.

Regarding the answer to "when" (idha) under both interpretations: It is said that it is the coming statement of the Exalted, "Woe, that Day, to the deniers." The omission of the fa (consecutive particle) in such instances occurs.

It is also said that it is omitted because the speech itself indicates it; that is, "Has the separation taken place?" or "Has what you were promised occurred?" Abu Hayyan chose this. It is permissible, based on the possibility that the answer is "Woe, that Day, to the deniers" or that the implied verb is postponed, for the sentence "To which Day has it been postponed?" to be a parenthetical clause intended to amplify the gravity of that Day.