Musnad Ahmad 30:2155

'Affan narrated to us, he said: Hammam narrated to us, he said: Qatadah narrated to us, from al-Hasan, from Ziyad ibn Riyah, from Abu Hurairah, that the Prophet, peace and blessings of Allah be upon him, said: "Hasten to perform deeds before six things: the rising of the sun from its place of setting, the Dajjal, the smoke, the beast of the earth, the private affair of one of you (death), and the affair of the masses (the Hour)." And Qatadah used to say, when he mentioned "the affair of the masses": "Meaning the affair of the Hour."