"A man from the tribe of Aslam came to the Prophet (saws) and confessed adultery. He turned away from him, the he confessed (again). Then he turned away from him (again) until he had testified against himself four times. So the Prophet (saws) said: "Are you insane?" He said:"No" He said: "Are you married?" He said: "Yes". So he gave the order and he was stoned at the Musalla. He ran when he was stuck by the stones, and he was caught and stoned until he died. So the Messenger of Allah (saws) spoke well of him but he did not perform the (funeral) Salat for him.

I heard the Prophet (PBUH) saying, "Dajjal (the Antichrist) will come forth and a person from amongst the believers will go towards him and the armed watchmen of Dajjal will meet him and they will say to him: 'Where do you intend to go?' He will say: 'I intend to go to this one who has appeared.' They will say to him: 'Don't you believe in our lord (meaning Dajjal)?' He will say: 'There (i.e., we know Him to be Allah, Alone, without any partners) is nothing hidden about our Rubb.' Some of them will say: 'Let us kill him', but some others will say: 'Has your lord (Dajjal) not forbidden you to kill anyone without his consent?' So they will take him to Dajjal. When the believer will see him, he will say: 'O people! This is Dajjal about whom the Messenger of Allah (PBUH) has informed us.' Dajjal will have him laid on his stomach and have his head. He will be struck on his back and on his stomach. Dajjal will ask him: 'Don't you believe in me?' He will say: 'You are the false Messiah.' He will then give his order to have him sawn with a saw into two from the parting of his hair up to his legs. After that Dajjal will walk between the two halves and will say to him: 'Stand up', and he will stand on his feet. He will then say to him: 'Don't you believe in me?' The person will say: 'It has added to my insight that you are Dajjal'. He will add: 'O people! He will not be able to behave with anyone amongst people in such a manner after me.' Dajjal will try to kill him. The space between his neck and collarbone will turn into copper and he will find no way to kill him. So he will catch hold of him by his hand and feet and throw him into (what appears to be the fire). The people will think that he has been thrown into the fire whereas he will be thrown into Jannah." The Messenger of Allah (PBUH) added, "He will be the most eminent amongst the people with regard to martyrdom near the Rubb of the worlds."

[Muslim]

Abu Sa'id al-Khudri reported God's messenger as saying, "When the dajjal comes forth one of the believers will go towards him, and the armed men, those of the dajjal, will meet him and ask him where he is making for. He will reply that he is making for this man who has come forth, whereupon they will ask him whether he does not believe in their lord, and when he replies, `There is nothing hidden about our Lord,' they will say, `Kill him.' But they will ask one another whether their lord has not forbidden them to kill anyone without his knowledge, and so they will take him to the dajjal; and when the believer sees him, he will say, `0 people, this is the dajjal whom God's messenger mentioned.' The dajjal will then order that he be stretched out, saying, `Take him and stretch him out.' After he has been given many blows on his back and stomach, he will ask him if he does not believe in him, but he will reply that he is the false Messiah. He will then order him to be sawn with a saw from the parting of his hair to between his legs, after which the dajjal will walk between the two pieces and tell him to get up. When he stands up he will ask him if he believes in him, to which he will reply that he has simply received more insight into his true nature, adding, `0 people, no one will be treated thus after me.' The dajjal will then seize him to cut his throat, but the space between bis neck and his collar-bone will be turned into copper and he will find no way by which he can kill him, so he will take him by the hands and feet and throw him into the air, and the people will think he has thrown him into hell, but he will simply have been thrown into paradise." God's messenger said, "This will be the one who suffers the severest martyrdom in the sight of the Lord of the universe." Muslim transmitted it.

Abu Hurairah (RAA) narrated, 'A Muslim man came to the Prophet (PBUH) while he was in the mosque, and called him saying, 'O Messenger of Allah! I have committed adultery.' The Messenger of Allah (PBUH) turned his face away from him, so the man came round (from the other side) towards his face and said, 'O Messenger of Allah! I have committed adultery.' The Messenger of Allah (PBUH) again turned his face away from him, but the man repeated his statement four times. When he testified four times that he did it, the Messenger of Allah (PBUH) called him saying, "Are you insane?" The man said, 'No.' The Messenger of Allah (PBUH) then asked him, "Are you married?" The man answered, 'Yes.' The Messenger of Allah (PBUH) said, "Take him away and stone him (to death)." Agreed upon.

And he did not narrate it in Marfu form, and this is more correct.