It is narrated from Sayyiduna Imran bin Husayn (may Allah be pleased with him), or another Companion, that the Messenger of Allah (peace and blessings be upon him) was on a journey when Surah al-Hajj was revealed. He (peace and blessings be upon him) recited it in a loud voice, while the people were dozing and their mounts had scattered: "O people, fear your Lord; indeed the quaking of the Hour is a tremendous thing" [Al-Hajj: 1] up to "but the punishment of Allah is severe" [Al-Hajj: 2]. So the people gathered around the Prophet (peace and blessings be upon him), thinking that the Hour had come. He (peace and blessings be upon him) said: "Do you know what day that will be?" They said: What day is it? He said: "It is the day on which Allah, the Mighty and Majestic, will say: 'O Adam, send forth the party of the Fire.' He will say: 'What is the party of the Fire?' He will say: 'From every thousand, nine hundred and ninety-nine to the Fire and one to Paradise.'" Hearing this, the people were struck dumb, until not one of them could show any cheerfulness. Then he (peace and blessings be upon him) said: "Keep doing good deeds and rejoice, for there has never been a prophethood without a period of ignorance (Jahiliyyah) before it, so the number will be completed from the people of Jahiliyyah, and whatever remains will be completed from the hypocrites." And he said: "Keep doing good deeds and rejoice, for you among the people are only like a mole on the side of a camel, or a mark on the foreleg of an animal. And you are between two creations which, whatever they were among, they made it numerous: Ya'juj and Ma'juj, along with those of the children of Adam and of Iblis who have perished."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15419