Narrated Abdullah bin Umar (may Allah be pleased with them): A group of the companions of the Prophet (peace and blessings of Allah be upon him), among whom was Umar (may Allah be pleased with him), set out with the Prophet (peace be upon him) towards Ibn Sayyad (a Jewish boy). Eventually, they found him playing with children near the hillocks of Banu Maghala (an Ansari tribe). Ibn Sayyad was close to puberty. He did not realize (the arrival of the Messenger of Allah, peace be upon him) until the Prophet (peace be upon him) approached him and struck his hand on his back and said, "Do you bear witness that I am the Messenger of Allah?" Ibn Sayyad looked at him and then said, "Yes! I bear witness that you are the Prophet of the unlettered." Then he asked the Prophet (peace be upon him), "Do you bear witness that I am the Messenger of Allah?" The Prophet (peace be upon him) replied only, "I believe in Allah and His (true) Prophets." Then the Prophet (peace be upon him) asked, "What do you see?" He said, "A truthful message comes to me, and sometimes a false one too." The Prophet (peace be upon him) said to him, "Your reality has become confused for you." The Prophet (peace be upon him) said to him, "Well, I have thought of something in my heart for you (tell me what it is)." Ibn Sayyad replied, "Smoke." The Prophet (peace be upon him) said, "Be disgraced, wretched one! You will not go beyond your status." Umar (may Allah be pleased with him) said, "O Messenger of Allah! Allow me to strike his neck." But the Prophet (peace be upon him) said, "If he is (the Dajjal), you will not be able to overpower him, and if he is not the Dajjal, then there is no good in killing him."

Abdullah bin Umar (may Allah be pleased with them) narrated that (on one occasion) the Messenger of Allah (peace and blessings of Allah be upon him) took Ubayy bin Ka'b (may Allah be pleased with him) along and came to the date-palm garden in which Ibn Sayyad was present. When the Prophet (peace be upon him) entered the garden, he began to advance, taking cover behind the trunks of the date-palms. He intended that Ibn Sayyad should not sense his presence and that he (the Prophet) could listen to his words. At that time, Ibn Sayyad was lying on his bed, covered with a sheet, and was murmuring something. Meanwhile, his mother saw the Messenger of Allah (peace be upon him) coming forward, taking cover behind the trunks of the date-palms, and she informed him, "O Saf!" (that was his name). As soon as Ibn Sayyad heard this, he jumped up. The Messenger of Allah (peace be upon him) said, "If his mother had left him as he was, the reality would have become clear."

Abdullah bin Umar (may Allah be pleased with them both) narrated that then the Prophet Muhammad (peace and blessings be upon him) addressed the companions: He praised Allah, as is befitting to His majesty. Then he mentioned the Dajjal, and said: I also warn you against his (trials), there has not been any prophet except that he warned his people against his trials; even Noah (peace be upon him) warned his people against him. But I will tell you something about him which no prophet told his people, and that is: the Dajjal will be one-eyed, and Allah, the Exalted, is free from such imperfection.