Musnad Ahmad 1693

It was narrated from "Abdullah bin Suraqah, that Abu "Ubadah bin al-Jarrah said: I heard the Messenger of Allah (ﷺ) say: "There was no Prophet (ﷺ) after Nooh but he warned his people about the Dajjal, and I am warning you of him." Then the Messenger of Allah (ﷺ) described him to us and said: "Perhaps some of those who saw me or heard my words will live to see him." They said: O Messenger of Allah, how will our hearts be on that day? Will they be as they are today? He said: "Orbetter.”