Then watch thou for the Day that the sky will bring forth a kind of smoke (or mist) plainly visible,
Enveloping the people: this will be a Penalty grievous.[Qur'an 44:10-11]
Abu Huraira(RA) reported Allah's Messenger (PBUH) having said: Hasten to do good deeds before six things happen: the rising of the sun from the west, the smoke, the Dajjal, the beast and (the death) of one of you or the general turmoil.