Umar and a group of the companions of the Prophet ﷺ set out with the Prophet to Ibn Saiyad. He found him playing with some boys near the hillocks of Bani Maghala. Ibn Saiyad at that time was nearing his puberty. He did not notice (the Prophet's presence) till the Prophet ﷺ stroked him on the back with his hand and said, "Ibn Saiyad! Do you testify that I am Messenger of Allah ﷺ?" Ibn Saiyad looked at him and said, "I testify that you are the Apostle of the illiterates." Then Ibn Saiyad asked the Prophet. "Do you testify that I am the apostle of Allah?" The Prophet ﷺ said to him, "I believe in Allah and His Apostles." Then the Prophet ﷺ said (to Ibn Saiyad). "What do you see?" Ibn Saiyad replied, "True people and false ones visit me." The Prophet said, "Your mind is confused as to this matter." The Prophet ﷺ added, " I have kept something (in my mind) for you." Ibn Saiyad said, "It is Ad-Dukh." The Prophet ﷺ said (to him), "Shame be on you! You cannot cross your limits." On that 'Umar said, "O Messenger of Allah ﷺ! Allow me to chop his head off." The Prophet ﷺ said, "If he should be him (i.e. Ad-Dajjal) then you cannot overpower him, and should he not be him, then you are not going to benefit by murdering him."  

أَنَّهُ أَخْبَرَهُ أَنَّ عُمَرَ انْطَلَقَ فِي رَهْطٍ مِنْ أَصْحَابِ النَّبِيِّ ﷺ مَعَ النَّبِيِّ ﷺ قِبَلَ ابْنِ صَيَّادٍ حَتَّى وَجَدُوهُ يَلْعَبُ مَعَ الْغِلْمَانِ عِنْدَ أُطُمِ بَنِي مَغَالَةَ وَقَدْ قَارَبَ يَوْمَئِذٍ ابْنُ صَيَّادٍ يَحْتَلِمُ فَلَمْ يَشْعُرْ حَتَّى ضَرَبَ النَّبِيُّ ﷺ ظَهْرَهُ بِيَدِهِ ثُمَّ قَالَ النَّبِيُّ ﷺ أَتَشْهَدُ أَنِّي رَسُولُ اللَّهِ ﷺ فَنَظَرَ إِلَيْهِ ابْنُ صَيَّادٍ فَقَالَ أَشْهَدُ أَنَّكَ رَسُولُ الأُمِّيِّينَ فَقَالَ ابْنُ صَيَّادٍ لِلنَّبِيِّ ﷺ أَتَشْهَدُ أَنِّي رَسُولُ اللَّهِ قَالَ لَهُ النَّبِيُّ ﷺ آمَنْتُ بِاللَّهِ وَرُسُلِهِ قَالَ النَّبِيُّ ﷺ مَاذَا تَرَى قَالَ ابْنُ صَيَّادٍ يَأْتِينِي صَادِقٌ وَكَاذِبٌ قَالَ النَّبِيُّ ﷺ خُلِطَ عَلَيْكَ الأَمْرُ قَالَ النَّبِيُّ ﷺ إِنِّي قَدْ خَبَأْتُ لَكَ خَبِيئًا قَالَ ابْنُ صَيَّادٍ هُوَ الدُّخُّ قَالَ النَّبِيُّ ﷺ اخْسَأْ فَلَنْ تَعْدُوَ قَدْرَكَ قَالَ عُمَرُ يَا رَسُولَ اللَّهِ ائْذَنْ لِي فِيهِ أَضْرِبْ عُنُقَهُ قَالَ النَّبِيُّ ﷺ إِنْ يَكُنْهُ فَلَنْ تُسَلَّطَ عَلَيْهِ وَإِنْ لَمْ يَكُنْهُ فَلاَ خَيْرَ لَكَ فِي قَتْلِهِ  

(Later on) Messenger of Allah ﷺ (once again) went along with Ubai bin Ka'b to the garden of date-palms where Ibn Saiyad was staying. When the Prophet entered the garden, he started hiding himself behind the trunks of the date-palms as he wanted to hear something from the Ibn Saiyad before the latter could see him. Ibn Saiyad was lying in his bed, covered with a velvet sheet from where his murmurs were heard. Ibn Saiyad's mother saw the Prophet ﷺ while he was hiding himself behind the trunks of the date-palms. She addressed Ibn Saiyad, "O Saf!" (And this was his name). Ibn Saiyad got up. The Prophet ﷺ said, "Had this woman let him to himself, he would have revealed the reality of his case." Then the Prophet ﷺ got up amongst the people, glorifying Allah as He deserves, he mentioned Ad-Dajjal, saying, "I warn you about him (i.e. Ad-Dajjal) and there is no prophet who did not warn his nation about him, and Noah warned his nation about him, but I tell you a statement which no prophet informed his nation of. You should understand that he is a one-eyed man and Allah is not one-eyed."  

انْطَلَقَ النَّبِيُّ ﷺ وَأُبَىُّ بْنُ كَعْبٍ يَأْتِيَانِ النَّخْلَ الَّذِي فِيهِ ابْنُ صَيَّادٍ حَتَّى إِذَا دَخَلَ النَّخْلَ طَفِقَ النَّبِيُّ ﷺ يَتَّقِي بِجُذُوعِ النَّخْلِ وَهْوَ يَخْتِلُ ابْنَ صَيَّادٍ أَنْ يَسْمَعَ مِنِ ابْنِ صَيَّادٍ شَيْئًا قَبْلَ أَنْ يَرَاهُ وَابْنُ صَيَّادٍ مُضْطَجِعٌ عَلَى فِرَاشِهِ فِي قَطِيفَةٍ لَهُ فِيهَا رَمْزَةٌ فَرَأَتْ أُمُّ ابْنِ صَيَّادٍ النَّبِيَّ ﷺ وَهْوَ يَتَّقِي بِجُذُوعِ النَّخْلِ فَقَالَتْ لاِبْنِ صَيَّادٍ أَىْ صَافِ وَهْوَ اسْمُهُ فَثَارَ ابْنُ صَيَّادٍ فَقَالَ النَّبِيُّ ﷺ لَوْ تَرَكَتْهُ بَيَّنَ وَقَالَ سَالِمٌ قَالَ ابْنُ عُمَرَ ثُمَّ قَامَ النَّبِيُّ ﷺ فِي النَّاسِ فَأَثْنَى عَلَى اللَّهِ بِمَا هُوَ أَهْلُهُ ثُمَّ ذَكَرَ الدَّجَّالَ فَقَالَ إِنِّي أُنْذِرُكُمُوهُ وَمَا مِنْ نَبِيٍّ إِلاَّ قَدْ أَنْذَرَهُ قَوْمَهُ لَقَدْ أَنْذَرَهُ نُوحٌ قَوْمَهُ وَلَكِنْ سَأَقُولُ لَكُمْ فِيهِ قَوْلاً لَمْ يَقُلْهُ نَبِيٌّ لِقَوْمِهِ تَعْلَمُونَ أَنَّهُ أَعْوَرُ وَأَنَّ اللَّهَ لَيْسَ بِأَعْوَرَ