2/80-82 — "A counted number of days"
"They said, 'The fire will not touch us except for a counted number of days.' Say: Have you taken a covenant from God?… No! Whoever earns an evil and is encompassed by his sin — those are the companions of the fire."
The claim is this: even if there is punishment it is limited, it has an end, it can be borne. This is the last stronghold of the "guarantee of chosenness" dismantled in verses 47-48 of the sūra — if there is no guarantee of salvation left, at least the shortness of the punishment is guaranteed.
The answer comes in two steps. First a proof is demanded: "Have you taken a covenant from God?" That is, what is the ground of this claim? Then the measure is set down.
وَأَحَٰطَتْ بِهِۦ خَطِيٓـَٔتُهُۥ — "if his sin has encompassed him". Root ḥ-w-ṭ: to surround, to enclose, to shut in. From the same root comes ḥāʾiṭ (a wall).
This word is chosen very carefully. The measure is not the number of sins; it is whether the sin has closed round the person. A person may err and his error may remain one part of him; or the error may grow and wall him in on every side, so that he now lives inside it. The verse describes the second.
The difference is this: in the first case the person still has a place from which he can look at his error — he can repent, he can turn back. In the second, the outside has become invisible. It comes out at the same place as the "seal" of the seventh verse of the sūra: the closing happens not in a moment but with the completion of the encirclement.