Narrated `Abdullah bin `Umar: `Umar bin Al-Khattab set out with Allah's Apostle, and a group of his companions to Ibn Saiyad. They found him playing with the boys in the fort or near the Hillocks of Bani Maghala. Ibn Saiyad was nearing his puberty at that time, and he did not notice the arrival of the Prophet till Allah's Apostle stroked him on the back with his hand and said, "Do you testify that I am Allah's Apostle?" Ibn Saiyad looked at him and said, "I testify that you are the Apostle of the unlettered ones (illiterates)". Then Ibn Saiyad said to the Prophets . "Do you testify that I am Allah's Apostle?" The Prophet denied that, saying, "I believe in Allah and all His Apostles," and then said to Ibn Saiyad, "What do you see?" Ibn Saiyad said, "True people and liars visit me." The Prophet said, "You have been confused as to this matter." Allah's Apostle added, "I have kept something for you (in my mind)." Ibn Saiyad said, "Ad-Dukh." The Prophet said, "Ikhsa (you should be ashamed) for you can not cross your limits." `Umar said, "O Allah's Apostle! Allow me to chop off h is neck." Allah's Apostle said (to `Umar). "Should this person be him (i.e. Ad-Dajjal) then you cannot over-power him; and should he be someone else, then it will be no use your killing him."