Jami` at-Tirmidhi Hadith 3254

"A man came to 'Abdullah and said: 'A story teller has said that a smoke will appear from the earth, taking the hearing of disbelievers and manifesting as a cold for the believers.'" He became angry, and since he was reclining, he sat up then said: 'When one of you is asked about something he knows, then let him speak accordingly' - Mansur (one of the narrators) narrated it as: "Then let him inform of it" - "And when asked about what he does not know, then let him say: "Allah knows best." For indeed, it is part of a man's knowledge, that when he is asked about something he does not know, he says: "Allah knows best." For verily Allah, Most High said to His Prophet: Say: "No wage do I ask of you for this, nor am I one of the pretenders (38:86)." When the Messenger of Allah (ﷺ) saw that the Quraish were behaving stubbornly with him, he said: "O Allah! Assist me against them with seven (years of famine) like the seven of Yusuf." So He punished them with drought making everything barren, until they ate skins and carcasses" - one of them said: "bones." He said: 'And it appeared that smoke was coming out of the earth. So Abu Sufyan came to him and said: "Verily your people are being destroyed, so supplicate to Allah for them." He said: "So this is about His saying: 'The Day when the sky will bring forth a visible smoke, covering the people, this is a painful torment (44:10 & 11).'" Mansur narrated it as: "So this is about His saying: Our Lord! Remove the torment from us, really we shall become believers (44:12)." - "So shall the punishment be removed from them in the Hereafter? Al-Batshah (humiliated defeat in Badr), Al-Lizam (disbeliever captives from Badr), the smoke," - one of them said: "The moon" the other said: "The Romans have all passed."