(Adukhan) 44 : 10
فَارْتَقِبْ يَوْمَ تَأْتِي السَّمَاءُ بِدُخَانٍ مُبِينٍ
Then you wait for a Day coming, when the sky covered with a manifest smoke.
As explained in verses 6: 158-159, the Lord of the universe has taught through His Messenger that the smoke which will spread throughout the Earth is one of the ten crucial signs of the Last Day. See explanation 43: 60-61.