Musnad Ahmad 27:356

Yazid narrated to us, Muhammad ibn Ishaq informed us, from Nafi’, from Ibn ‘Umar, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "There was no prophet before me but that he described him [the Dajjal] to his nation, and I shall describe him with a description that no one before me has described: He is one-eyed, and Allah, Blessed and Exalted is He, is not one-eyed. His right eye is as if it were a floating grape."