فَكَيْفَ كَانَ عَذَابِى وَنُذُرِ
This sentence occurs six times in the sūra; four in this form (16, 18, 21, 30), two in the imperative (37, 39).
كَيْفَ is a particle that asks after a state: "how". But here it is not a genuine request for information.
- The confirmatory question — one whose answer is known, asked in order to make the addressee concede it.
- The question of wonder — one that conveys astonishment and dread.
- The question of threat — one that conveys a threat.
All three have been defended for this sentence, and there is no sharp boundary between them. In rendering it into English, an exclamation mark rather than a question mark falls closer to the function of the sentence: "How was My punishment!"
In al-Mulk two sentences of exactly this pattern were treated: fa-kayfa kāna nakīr (67/18) and kayfa kāna nadhīr (67/17). I rely on the analysis there and do not repeat it.
And this is the most striking side of the sentence. The sentence is said to people who have not yet seen the punishment, about people who have — but the tense states that the event is over.
I record this as my own reading: this choice of tense places the addressee after the event. He hears, in the past tense, of something that has not yet come to him in the state in which it came to others. This is what the sūra does: it shows the future in the language of the past.
And this belongs to the same family as the grammatical question of the first verse. There iqtarabat was perfect and related something that had not yet happened. Here kāna is perfect and shows something that has happened to a community to whom it has not yet happened. The sūra bends the tenses in both directions at once.
ʿAdhābī — "my punishment". Nudhur — as was shown above in the section on verse-endings, its original is nudhurī; the yāʾ has been dropped for the verse-ending.
That the two words stand side by side is worth recording. ʿAdhāb is punishment; nudhur is warning. One is the outcome, the other what preceded it. The sentence gathers the two into one question: "How was My punishment — and how were My warnings!"
And what follows from this is: the warning is named as part of the punishment. The warnings too are the subject of the question "how was it". The verse asks, that is, not only about the severity of the penalty but about whether what was done before the penalty had also been carried out.
I record this as my own reading; its ground is that the two words are joined under a single attribution, and this is verifiable data of the word order.