فَلَمَّا جَآءَ ءَالَ لُوطٍ ٱلْمُرْسَلُونَ · قَالَ إِنَّكُمْ قَوْمٌ مُّنكَرُونَ · قَالُوا۟ بَلْ جِئْنَٰكَ بِمَا كَانُوا۟ فِيهِ يَمْتَرُونَ · وَأَتَيْنَٰكَ بِٱلْحَقِّ وَإِنَّا لَصَٰدِقُونَ
Fa-lammā jāʾa āla Lūṭini'l-mursalūn · Qāla innakum qawmun munkarūn · Qālū bal jiʾnāka bimā kānū fīhi yamtarūn · Wa ataynāka bi'l-ḥaqqi wa innā la-ṣādiqūn
"When the messengers came to the family of Lot, · Lot said: 'You are people unknown.' · They said: 'No, we have brought you the very thing they kept doubting. · We have brought you the truth; we are truthful.'"
The ن-ك-ر root: not to recognise, to find strange. Munkar — unrecognised; and from this, "not welcomed, rejected".
The same expression occurred at al-Dhāriyāt 51/25 out of Abraham's mouth: qāla salāmun qawmun munkarūn. The same sentence in two scenes, in the mouths of two different prophets. This is a repetition that can be verified.
I record this as an observation about the word order: the sūra opens two encounters with the same word. In both the first reaction is not to recognise — and in both the guests introduce themselves with a piece of news.
The م-ر-ي root: to doubt, to dispute. Mirya — doubt. The lexicographers record the concrete sense of the root as "to tug at the udder in order to milk it", and explain doubt by the picture of "tugging a matter back and forth".
And the object of the word must be recorded: bimā kānū fīhi yamtarūn — "the thing they kept doubting." That is, what is brought is the very thing that was being disputed.
I record this as an observation: the answer does not give the name of the punishment. It names it by the other side's own doubt. What they were disputing is coming.