Sahih Bukhari Volume 2, Book 23, Hadith 1355

حَدَّثَنَا عَبْدَانُ، أَخْبَرَنَا عَبْدُ اللَّهِ، عَنْ يُونُسَ، عَنِ الزُّهْرِيِّ، قَالَ أَخْبَرَنِي سَالِمُ بْنُ عَبْدِ اللَّهِ، أَنَّ ابْنَ عُمَرَ ـ رضى الله عنهما ـ أَخْبَرَهُ أَنَّ عُمَرَ انْطَلَقَ مَعَ النَّبِيِّ صلى الله عليه وسلم فِي رَهْطٍ قِبَلَ ابْنِ صَيَّادٍ، حَتَّى وَجَدُوهُ يَلْعَبُ مَعَ الصِّبْيَانِ عِنْدَ أُطُمِ بَنِي مَغَالَةَ، وَقَدْ قَارَبَ ابْنُ صَيَّادٍ الْحُلُمَ فَلَمْ يَشْعُرْ حَتَّى ضَرَبَ النَّبِيُّ صلى الله عليه وسلم بِيَدِهِ ثُمَّ قَالَ لاِبْنِ صَيَّادٍ ‏"‏ تَشْهَدُ أَنِّي رَسُولُ اللَّهِ ‏"‏‏.‏ فَنَظَرَ إِلَيْهِ ابْنُ صَيَّادٍ فَقَالَ أَشْهَدُ أَنَّكَ رَسُولُ الأُمِّيِّينَ‏.‏ فَقَالَ ابْنُ صَيَّادٍ لِلنَّبِيِّ صلى الله عليه وسلم أَتَشْهَدُ أَنِّي رَسُولُ اللَّهِ فَرَفَضَهُ وَقَالَ آمَنْتُ بِاللَّهِ وَبِرُسُلِهِ‏.‏ فَقَالَ لَهُ ‏"‏ مَاذَا تَرَى ‏"‏‏.‏ قَالَ ابْنُ صَيَّادٍ يَأْتِينِي صَادِقٌ وَكَاذِبٌ‏.‏ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ خُلِّطَ عَلَيْكَ الأَمْرُ ‏"‏ ثُمَّ قَالَ لَهُ النَّبِيُّ صلى الله عليه وسلم ‏"‏ إِنِّي قَدْ خَبَأْتُ لَكَ خَبِيئًا ‏"‏‏.‏ فَقَالَ ابْنُ صَيَّادٍ هُوَ الدُّخُّ‏.‏ فَقَالَ ‏"‏ اخْسَأْ، فَلَنْ تَعْدُوَ قَدْرَكَ ‏"‏‏.‏ فَقَالَ عُمَرُ ـ رضى الله عنه ـ دَعْنِي يَا رَسُولَ اللَّهِ أَضْرِبْ عُنُقَهُ‏.‏ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ إِنْ يَكُنْهُ فَلَنْ تُسَلَّطَ عَلَيْهِ، وَإِنْ لَمْ يَكُنْهُ فَلاَ خَيْرَ لَكَ فِي قَتْلِهِ ‏"‏‏

Narrated By 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 over-power him, and if he is not, then there is no use of murdering him."