On the Day the sky will be like murky oil, (70:8)

Almuntakhab Fi Tafsir Alquran Alkarim

That is the Day when the heavens shall look like a metallic substance melted in oil

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(70:8) It shall befall on a Day *8 whereon the sky will become like molten brass, *9

On the Day the sky will be like murky oil, meaning

*8) A section of the commentators regard this sentence as related to "a day whose measure is fifty thousand years"; they say that the day whose measure has been stated to be fifty thousand years is the Day of Resurrection. In Musnad Ahmad and in the Tafsir by Ibn Jarir, a tradition has been related on the authority of Hadrat Abu Sa'id Khudri, saying: "When wonder and amazment was expressed before the Holy Prophet (upon whom be peace) about the length of this Day with reference to this verse, he replied: 'By Him in Whose hand is my life, the believer will find the Day even lighter (of shorter duration) than the time he takes in performing an obligatory Prayer in the world" . " Had this tradition been reported through authentic channels, this verse could not be interpreted in any other way, but two of its transmitters, Darraj and his teacher Abul Haytham, are both weak and untrustworthy.
*9) That is, it will change its colour over and over again.
 

On the Day the sky will be like murky oil, meaning in Urdu

(وہ عذاب اُس روز ہوگا) جس روز آسمان پگھلی ہوئی چاندی کی طرح ہو جائے گا