Sahih Bukhari Volume 009, Book 093, Hadith Number 505.

Narrated By Anas : The Prophet said, "Allah did not send any prophet but that he warned his nation of the one-eyed liar (Ad-Dajjal). He is one-eyed while your Lord is not one-eyed, The word 'Kafir' (unbeliever) is written between his two eyes."