John 21:20-23

Peter turned and saw that the disciple whom Jesus loved was following them. (This was the one who had leaned back against Jesus at the supper and had said, “Lord, who is going to betray you?”) When Peter saw him, he asked, “Lord, what about him?” Jesus answered, “If I want him to remain alive until I return, what is that to you? You must follow me.” Because of this, the rumor spread among the believers that this disciple would not die. But Jesus did not say that he would not die; he only said, “If I want him to remain alive until I return, what is that to you?”