Yāsīn 36:63-64

Hādhihī jahannamu'llatī kuntum tūʿadūn · Iṣlawha'l-yawma bimā kuntum takfurūn

"This is the Hell you were promised. Enter it today, for the denial you persisted in."

A point of word order: hādhihī — "this here." And in the sixty-first verse hādhā ṣirāṭun mustaqīm had been said — a demonstrative there too.

Two demonstratives three verses apart. My own reading: both are sentences of pointing, and both point to something already spoken of. In the scene there is no longer any describing; there is pointing. The same attitude runs through this whole section of the sūra: al-yawma five times, the demonstrative twice.

The verb is passive and in the durative form: kuntum tūʿadūn — "you were being promised."

Worth recording: the word is tūʿadūn — from the root و-ع-د. In Arabic waʿd is neutral: it is used both for good and for ill (waʿīd, by contrast, is only for a threat). Here waʿd is used of Hell.

And a link inside the sūra can be verified: in the fifty-second verse those raised had said hādhā mā waʿada'r-Raḥmān — the same root. Two occurrences: one for the resurrection itself, the other for Hell. In both, what is said is the coming to pass of what was announced beforehand.

The root: to enter fire, to be scorched in fire, to be exposed to burning fire. In al-Wāqiʿa taṣliya (56/94) was treated — a Form II verbal noun, announcing the performing of the act. I do not repeat it here.

What belongs here: here it is a Form I imperative (iṣlaw) — that is, the act of entering the fire is commanded to the persons themselves. In al-Wāqiʿa the act was something done to them (taṣliya); in Yāsīn it is commanded of them. This difference can be verified.

A point of word order, and it sets up a pattern within the sūra. In this section the same pattern comes three times:

All three have the pattern kāna + imperfect — that is, an ongoing, repeated act. My own reading: the recompense is tied not to a single moment but to a state that has lasted. The pattern announces not a momentary decision but a habit.

ك-ف-ر — the core of the root is to cover. Kāfir is explained by the lexicographers with the examples of "the farmer who covers the seed with earth" and "the darkness that covers the night". The root has been treated in many places in the index; I do not repeat it here.

And the placing of the root here is worth recording: in the ninth verse of the sūra a covering had been drawn over them (fa-aghshaynāhum). Here, as the ground, a root of covering is named once more. I give this as an observation; I make no point of it.