Sahih Bukhari
Afflictions and the End of the World
Volume: 009 / Book Number: 088 / Hadith Number: 245
Narrated Anas:
The Prophet said, "No prophet was sent but that he warned his followers against the one-eyed liar (Ad-Dajjal). Beware! He is blind in one eye, and your Lord is not so, and there will be written between his (Ad-Dajjal's) eyes (the word) Kafir (i.e., disbeliever)." (This Hadith is also quoted by Abu Huraira and Ibn 'Abbas).