It is narrated from Masruq, he says: Once a man was giving a sermon in the Great Mosque of Kufa, saying that on the Day of Resurrection, smoke will descend from the sky, which will seize the ears and eyes of the hypocrites, and its effect on the believers will be that they will feel as if they have a cold. Hearing this, I went to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) and mentioned this matter to him. He was sitting reclining, but as soon as he heard this, he sat up straight and said: O people! When you are asked a question of knowledge, if you know it, then answer it, and if you do not know, then say: Allah knows best (Allah is the All-Knowing). Indeed, it is also knowledge to say "Allah knows best" about something you do not know. See, Allah Almighty said to His Prophet: {قُلْ مَا أَسْأَلُکُمْ عَلَیْہِ مِنْ أَ جْرٍ وَمَا أَ نَا مِنْ الْمُتَکَلِّفِینَ} … Say: I do not ask you for any reward for this, nor am I one of those who pretend. When the Quraysh overpowered the Prophet (peace and blessings be upon him) and became rebellious against him, the Prophet (peace and blessings be upon him) supplicated against them with these words: O my Allah! Help me against them by imposing on them a seven-year famine like that of Yusuf (Joseph, peace be upon him). So they were afflicted with such famine that they began to eat bones and carrion. They were so distressed and troubled that due to hunger, they would see something like smoke between themselves and the sky. Eventually, they said: O our Lord! Remove this punishment from us, we are believers. It was said to the Prophet (peace and blessings be upon him): If the punishment is removed from them, they will return to their former state. The Prophet (peace and blessings be upon him) prayed to his Lord, and He removed the punishment from them, but when they returned to the same state of disobedience, Allah Almighty seized them on the day of Badr. These are the situations referred to in Allah Almighty's statement: {فَارْتَقِبْ یَوْمَ تَأْتِی السَّمَائُ بِدُخَانٍ مُبِینٍ … … یَوْمَ نَبْطِشُ الْبَطْشَۃَ الْکُبْرٰی إِنَّا مُنْتَقِمُونَ}. In the hadith of Ibn Numayr, Sayyiduna Abdullah (may Allah be pleased with him) said: If this smoke were to be on the Day of Resurrection, then it would not be removed from them.