70:8
يَوْمَ تَكُونُ ٱلسَّمَآءُ كَٱلْمُهْلِ
yawma takūnu l-samāu kal-muh'li
On the Day the sky will be like murky oil,
— Saheeh International
On a Day when the heavens will be like molten brass
— M. A. S. Abdel Haleem
The Day that the sky will be like the boiling filth of oil, (or molten copper or silver or lead).
— Muhammad Muhsin Khan & Muhammad Taqi-ud-Din al-Hilali