Musannaf Ibn Abi Shayba 37:364

Yazid ibn Harun narrated to us, from Abu Malik al-Ashja'i, from Rib'i, from Hudhayfah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "I am more knowledgeable of what is with the Dajjal than the Dajjal himself. With him are two flowing rivers: one of them, to the naked eye, is white water, and the other, to the naked eye, is a blazing fire. So if anyone of you reaches that, let him come to the river which he sees as fire, then let him close his eyes, then let him lower his head and drink, for it is cold. And the Dajjal is one-eyed, upon his eye is a thick film, and written between his eyes is 'Kafir' (disbeliever). Every believer will recognize him, whether literate or illiterate."