Sayyidina Abu Ubaydah ibn Jarrah (RA) reported that he heard Allah’s Messenger (SAW) say, “There has not been a Prophet (SAW) after Nuh who has not warned his people of dajjal. And I warn you of him.’ And he described him for them, saying, “Perhaps of those who see me or hear my words, some might encounter him.” They submitted, “O Messenger of Allah, (SAW) , how will (the condition of) our hearts be on that day?” He said, “Like this (as today) or better”
[Ahmed 1693].