Sura al-Dukhān 44:10

فَٱرْتَقِبْ يَوْمَ تَأْتِى ٱلسَّمَآءُ بِدُخَانٍ مُّبِينٍ

fa-irtaqib yawma tatī l-samāʾu bi-dukhānin mubīnin

Then watch thou for the Day that the sky will bring forth a kind of smoke (or mist) plainly visible,

Sura al-Dukhān 44:59

فَٱرْتَقِبْ إِنَّهُم مُّرْتَقِبُونَ

fa-irtaqib innahum murtaqibūna

So wait thou and watch; for they (too) are waiting.