Tafsir of An-Naba' 78:21

"A place of ambush" (Mirṣād): The limit where the ambush is set. The meaning is that Hell is the limit for the transgressors where they are ambushed for punishment, and it is their destination. Alternatively, it is an ambush for the people of Paradise; the angels who receive them there lie in wait, because their path passes over it, while it remains a destination for the transgressors. Al-Hasan and Qatadah said something similar: it is a path and a passage for the people of Paradise.

Ibn Ya‘mar read “anna jahannama” (that Hell) with a fatḥah on the hamzah, as an explanation for the establishment of the Hour—as if to say: "That was for the establishment of retribution."

"Remaining" (Lābithīn) and "Abiding" (Labithīn): Labithīn is stronger, because the lābith (abider) is one from whom the act of abiding originates. One is not called labith unless abiding is his nature, like one who squats in a place and can hardly be separated from it.

"For ages" (Aḥqāban): Age after age. Whenever one age passes, another follows it without end. Ḥuqb and ḥuqbah are only used when the succession and continuity of time are intended, as evidenced by their derivation. Do you not see the ḥaqībah (saddlebag) of the rider, or the ḥaqab (strap) behind the girth? It is said: a ḥuqb is eighty years. It is possible that the meaning is: abiding therein for ages, not tasting therein coolness nor drink, except for boiling water and pus, then after those ages, they are replaced with another kind of punishment.

Another interpretation: It is from the phrase "our year has become ḥaqaba" (when its rain and goodness are scarce). A man is ḥaqib when provision misses him. Thus, it is a state (ḥāl) describing them, meaning: abiding therein, deprived and cut off.

"They will not taste therein coolness nor drink": This is an explanation of the previous state. The exception is munqaṭi‘ (discontinuous), meaning: they will not taste therein coolness or relief that eases the heat of the Fire, nor drink that settles their thirst; rather, they taste boiling water and pus. It is said that "coolness" (al-bard) means sleep. A poet said: "If I wished, I would forbid women other than you / And if I wished, I would not taste sleep nor coolness." Some Arabs say: "May the cold prevent the cold (sleep)."

"Pus" (Ghassāqan): Read with both light and heavy sīn. It is that which yaghsuqu—that is, flows from their wounds.

"Appropriate" (Wifāqan): Described by the verbal noun, or meaning "possessing appropriateness." Abu Ḥaywah read it as wifāqan (a fi‘āl form from wafaqa).

"Denial" (Kidhābā): Read as kidhābā (with a short i), which is the verbal noun of kadhaba. This is like the verse: "And caused you to grow from the earth a [progressive] growth" (Nūḥ: 17). It means: they denied Our signs, so they denied them with a denial. Or, it is governed by kadhḍabū because it contains the meaning of kadhḍabū, for every denier of the truth is a liar. If you take it as meaning "mutual denial," it means they denied Our signs, so they engaged in mutual denial. Or, they spoke with an excess of lying, like one who competes in a matter and exerts his utmost effort.

It is also read as kidhābā (plural of kādhib), meaning: they denied Our signs while being liars. Kidhāb can also mean a single person who is eloquent in lying, like saying ḥassān or bakhāl. It is made an attribute of the verbal noun of kadhḍabū, meaning: a denial that is excessive in its falsehood.

"And everything We have counted" (Wa-kulla shay’in aḥṣaynāhu): Read in the nominative as an initial subject.

"In a record" (Kitābā): A verbal noun in the place of "counting." Aḥṣaynā (We have counted) is in the meaning of katabnā (We have written), for counting and writing both imply recording and preservation. Or, it is a state (ḥāl) meaning: written on the Preserved Tablet and in the scrolls of the recording angels. The meaning is the counting of their sins, as in: "Allah has enumerated it, while they forgot it" (Al-Mujādilah: 6). This is a parenthetical clause.

"So taste [the penalty]": This is a consequence of their disbelief in the reckoning and their denial of the signs. This is a verse of extreme severity. It is enough for you that it says, "We will not increase you," and its indication that the cessation of increase is like an impossibility that cannot be conceived. Its arrival in the style of iltifāt (shifting of address) is a witness that the wrath has reached its peak. The Prophet (peace be upon him) said: "This verse is the most severe in the Quran for the people of the Fire."