Musnad Ahmad 30:2234

'Affan narrated to us, Hammad ibn Salamah narrated to us, from 'Ata' ibn Abi Maymunah, from Abu Rafi', from Abu Hurayrah, that the Messenger of Allah (peace and blessings of Allah be upon him) used to say: "O Allah, I seek refuge in You from the trial of life and death, and from the evil of the False Messiah (Al-Masih ad-Dajjal)."