Tafsir of Ad-Dukhan 44:9

Then He refuted their being certain by His saying: {Nay, they are in doubt, playing}, meaning that their acknowledgment does not stem from knowledge or certainty, nor from seriousness or truth; rather, it is speech mixed with mockery and play.

{The day the sky will bring}: The object of the verb murtaqib (awaiting). It is said: raqabtu-hu and irtaqabtu-hu, similar to nazartu-hu and intazartu-hu.

There is disagreement regarding the "smoke" (ad-dukhan):

• From Ali ibn Abi Talib (may Allah be pleased with him), and Hasan adopted this view: It is a smoke that comes from the sky before the Day of Resurrection. It enters the ears of the disbelievers until the head of one of them becomes like a roasted head (hanidh), while it affects the believer only like a cold. The entire earth will be like a house in which a fire has been kindled, with no ventilation.
• From the Messenger of Allah (peace be upon him): "The first of the signs are: the smoke, the descent of Isa ibn Maryam, and a fire that emerges from the depths of Aden-Abyan driving the people to the place of gathering." Hudhayfah asked: "O Messenger of Allah, what is the smoke?" The Messenger of Allah (peace be upon him) recited the verse and said: "It fills what is between the East and the West, remaining for forty days and nights. As for the believer, it affects him like a cold, and as for the disbeliever, he is like one intoxicated, with it exiting from his nostrils, ears, and anus."
• From Ibn Mas’ud (may Allah be pleased with him): Five [signs] have already passed: ar-Rum, the smoke, the moon, the batsha (seizure), and the lizam (inevitable punishment). It is narrated that it was said to Ibn Mas’ud: "A storyteller at the gates of Kindah says that it is a smoke that will come on the Day of Resurrection and seize the breaths of creation." He replied: "Whoever has knowledge, let him speak with it, and whoever does not know, let him say: 'Allah knows best,' for it is part of a man's knowledge to say of what he does not know: 'Allah knows best.'"

Then he said: "I shall tell you: When the Quraysh defied the Messenger of Allah (peace be upon him), he prayed against them, saying: 'O Allah, tighten Your grip on Mudar, and make them years like the years of Yusuf.' They were struck by such hardship that they ate carcasses and al-’ilhiz (a mixture of fur and blood). A man would see smoke between the sky and the earth; a man would speak to another, but he could not see him because of the smoke. Abu Sufyan and a group with him went to him, adjured him by Allah and kinship, and promised that if he prayed for them and it was lifted, they would believe. When it was lifted, they returned to their polytheism."

{With a clear smoke}: Its state is manifest; no one doubts that it is smoke. {Covering the people}: Enveloping and clothing them. It is in the genitive case as an adjective for "smoke."

{This is a painful torment} up to His saying {believers}: The position is accusative due to an implied verb, which is "they say." "And they say" is in the accusative state as a circumstantial qualifier (hal), meaning: saying that. {We are believers}: A promise of faith if the torment is lifted from them.

{How can they have the reminder, when there had come to them a clear Messenger? Then they turned away from him and said, "A taught madman!" Indeed, We will lift the torment a little, but indeed, you will return [to disbelief]. The Day We will strike with the greatest strike, indeed, We will take retribution.}