Sahih Bukhari Volume 9, Book 88, Hadith Number 241.

Narrated By Abdullah bin Umar : Allah’s Apostle stood up amongst the people and then praised and glorified Allah as He deserved and then he mentioned Ad-Dajjal, saying, “I warn you of him, and there was no prophet but warned his followers of him; but I will tell you something about him which no prophet has told his followers: Ad-Dajjal is one-eyed whereas Allah is not.”