Narrated Ibn `Umar: `Umar set out along with the Prophet (p.b.u.h) with a group of people to Ibn Saiyad till they saw him playing with the boys near the hillocks of Bani Mughala. Ibn Saiyad at that time was nearing his puberty and did not notice (us) until the Prophet stroked him with his hand and said to him, Do you testify that I am Allah's Apostle? Ibn Saiyad looked at him and said, I testify that you are the Messenger of illiterates. Then Ibn Saiyad asked the Prophet (p.b.u.h), Do you testify that I am Allah's Apostle? The Prophet (p.b.u.h) refuted it and said, I believe in Allah and His Apostles. Then he said (to Ibn Saiyad), What do you think? Ibn Saiyad answered, True people and liars visit me. The Prophet said, You have been confused as to this matter. Then the Prophet said to him, I have kept something (in my mind) for you, (can you tell me that?) Ibn Saiyad said, It is Al-Dukh (the smoke). (2) The Prophet said, Let you be in ignominy. You cannot cross your limits. On that `Umar, said, O Allah's Apostle! Allow me to chop his head off. The Prophet (p.b.u.h) said, If he is he (i.e. Dajjal), then you cannot overpower him, and if he is not, then there is no use of murdering him.