John 21:20-23 - Peter And The Other Disciple Jesus Loved
20 Peter turned around and noticed the disciple whom Jesus kept loving following them. He was the one who had put his head on Jesus' chest at the supper and had asked, "Lord, who is the one who is going to betray you?" 21 When Peter saw him, he said, "Lord, what about him?"
22 Jesus told him, "If it's my will for him to remain until I come back, how does that concern you? You must keep following me!"
23 So the rumor spread among the brothers that this disciple wasn't going to die. Yet Jesus didn't say to Peter that he wasn't going to die, but, "If it's my will for him to remain until I come back, how does that concern you?"