From Sahih Bukhari (Hadith 7408):
Narrated Anas:The Prophet (ﷺ) 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
Reference: Bukhari 7408