ما هو المقصود بالدخان كإحدى علامات الساعة الكبرى؟

There are two differing opinions regarding the "smoke" (Dukhan) mentioned in the Qur'an:

The first is that it refers to the severe hardship and hunger that befell the Quraysh, to the extent that they saw the sky as if it were smoke. This is the opinion of Abdullah ibn Mas'ud, may Allah be pleased with him.

The second is that it is a sign yet to come, which will occur near the Hour, and it will be a real smoke that envelops people. This is the opinion of Ibn Abbas and some of the Companions and Tabi'un (followers).

It is possible to reconcile these two opinions by suggesting that there are two kinds of smoke: one that has already passed (what befell the Quraysh), and another that has not yet come and will be one of the major signs of the Hour.