Surah Ad-Dukhan 44:45

كَٱلْمُهْلِ يَغْلِى فِى ٱلْبُطُونِ

Like murky oil, it boils within bellies

Translation: Saheeh International

Tafsir

Like molten copper that is to say like the dregs of black oil ka’l-muhli is the second predicate it will boil inside the bellies if read taghlī then it is a third predicate; if yaghlī then it is a circumstantial qualifier referring to al-muhl ‘molten copper’

Excerpt from Tafsir al-Jalalayn, commentary on 44:45, via Quran.com. The reader has the full commentary and 9 more tafsirs.