From Sahih Bukhari (Hadith 7131):
Narrated Anas:The Prophet (ﷺ) 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)
Reference: Bukhari 7131