Abu Sa'id Al-Khudri (May Allah be pleased with him) reported:
I heard the Prophet (ﷺ) 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 (ﷺ) 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 (ﷺ) added, "He will be the most eminent amongst the people with regard to martyrdom near the Rubb of the worlds."[Muslim]
App reference: Book 19, Hadith 8
Arabic/English book reference: Book 19, Hadith 1815