﴿ فَٱرْتَقِبْ يَوْمَ تَأْتِى ٱلسَّمَآءُ بِدُخَانٍۢ مُّبِينٍۢ ﴾

“WAIT, THEN, for the Day when the skies shall bring forth a pall of smoke which will make obvious [the approach of the Last Hour],”

God exalted be He says So watch out for the day when the heaven will produce a visible smoke. Thus the earth became barren and famine became so severe that they began to see what looked like smoke rising between the heaven and the earth