John 21:20-23 - Peter And The Other Disciple Jesus Loved
20 Peter turned around and saw the disciple whom Jesus loved following them. (This was the disciple who had leaned back against Jesus' chest at the meal and asked, "Lord, who is the one who is going to betray you?") 21 So when Peter saw him, he asked Jesus, "Lord, what about him?"
22 Jesus replied, "If I want him to live until I come back, what concern is that of yours? You follow me!"
23 So the saying circulated among the brothers and sisters that this disciple was not going to die. But Jesus did not say to him that he was not going to die, but rather, "If I want him to live until I come back, what concern is that of yours?"