فَٱرْتَقِبْ يَوْمَ تَأْتِى ٱلسَّمَآءُ بِدُخَانٍ مُّبِينٍ
Fartaqib Yawma taatis samaaa'u bidukhaanim mubeen
[Prophet], watch out for the Day when the sky brings forth clouds of smoke for all to see.
So watch for the day when the sky brings forth a visible smoke,