It was narrated that Hudhaifah said:
The Messenger of Allah said: 'I know what the Dajjal will have with him. He will have two flowing rivers, one that appears to the eye to be clear water, and one that appears to the eye to be flaming fire. If anyone sees that, let him go to the river which he thinks is fire and close his eyes, then lower his head and drink from it, for it is cool water. The Dajjal has one blind eye, with a layer of thick skin over it, and between his eyes is written disbeliever, which every believer will read, whether he is literate or illiterate.'