Musnad Abu Ya'la al-Mawsili 42:438

Abu Sa’id al-Khudri said: The Messenger of Allah (ﷺ) said: "The Dajjal will emerge, and a man from the Muslims will head toward him. The guards of the Dajjal will meet him and say to him, 'Where are you intending to go?' He will say, 'I intend to go to this one who has emerged.' They will say, 'Do you not believe in our Lord?' He will say, 'I do not see [that he is anything]; I do not consider him to be the truth.' They will say, 'Kill him.' Some of them will say to others, 'Has your Lord not forbidden you to kill anyone without his [permission]?' So they will take him to the Dajjal. When the believer sees him, he will say, 'O people, this is the Dajjal whom the Messenger of Allah (ﷺ) mentioned.' The Dajjal will then order him to be stretched out. He will say, 'Take him and stretch him out.' So he will be stretched out, and his back and stomach will be struck. He will say to him, 'Do you not believe in me?' He will say, 'You are the lying Messiah.' He will then order him to be sawed with a saw from the parting of his hair until he is separated between his legs. Then the Dajjal will walk between the two pieces, and then he will say, 'Stand up.' He will stand up straight. He will say to him, 'Do you not believe in me?' He will say, 'I have only increased in insight regarding you.' Then he will say, 'O people, he will not do to anyone among the people what he has done to me.' The Dajjal will then take him to slaughter him, but the area between his collarbone and his throat will be made into copper, so he will have no way to [slaughter] him. He will then take him by his hands and feet and throw him, and the people will think he threw him into the Fire, but he was only cast into Paradise." The Messenger of Allah (ﷺ) said: "This is the greatest of people in martyrdom before the Lord of the Worlds."