Tafsir of Ta-Ha 20:103

(They whisper among themselves): That is, they lower their voices and conceal them due to the intensity of the horror of the event. The sentence is an initiation (istī’nāf) to explain what they will say and what they will leave behind at that time, or it is another state (ḥāl) for the "criminals."

His saying—the Exalted—(that you have remained) involves an elliptical saying that serves as a state (ḥāl) for the pronoun in "they whisper," meaning: saying, "You have not remained in the graves except for ten [days/nights]."

(Ten): That is, ten nights or ten days; perhaps this is more consistent with the statement of the "most just among them." When the masculine is omitted while keeping its number, the tā’ (feminine marker) may not be brought; Al-Kisa'i narrated: "We fasted five [days] of the month." From this is what appeared in the Hadith: "Then followed it with six [days] of Shawwal," for the intent is six days. The omission is made beautiful here by the fact that it is a verse-ending (fāṣilah). Their intent in this statement is to deem the duration short and its passing rapid, and to express regret over what they used to claim, as the matter has become clear to be contrary to what they were upon regarding the denial of the Resurrection and counting it among the impossible. It is as if they said: "You have been resurrected, and you did not remain in the grave except for a short period, whereas you used to claim that you would never rise from it."

From Qatadah, it is reported that they meant their dwelling in the world, and they said that out of deeming the duration of their stay therein as short due to its vanishing, and deeming the duration of the Hereafter as long, or due to their regret over it once they witnessed the calamities and became certain that they deserved them for wasting days in fulfilling desires and following passions. This has been critiqued by the observation that they are in a state of overwhelming distraction that prevents them from remembering that; therefore, what was previously mentioned is more consistent with their state. It is also critiqued by the fact that the saying of the Exalted—"You have remained in the Book of Allah until the Day of Resurrection"—is explicit that it refers to the remaining in the graves, though there is some discussion regarding this.

In Majma' al-Bayān, it is reported from Ibn Abbas and Qatadah that they meant their dwelling between the two trumpet blasts, remaining for forty years during which the punishment is lifted from them.