and [the signs of] the Romans and the Moon.
Muhammad said: Hunger was referred to as 'smoke' due to the dryness of the earth during the year of drought, the cutting off of vegetation, and the rising of dust; thus, what rose from it was likened to smoke. It is part of their speech: a 'dusty' famine and a 'dusty' year for a year of famine.
Interpretation of Surah Ad-Dukhan from verse 17 to verse 29.
