John 21:20-23 - Peter And The Other Disciple Jesus Loved
20 Peter turned around and saw the disciple whom Jesus loved [i.e., probably the apostle John] following [along behind him]. This was the same disciple who had leaned over close to Jesus at the [Passover] meal and asked Him, "Lord, who is it that will turn you over [to the Jewish authorities]?" 21 [When] Peter saw this disciple, he said to Jesus, "Lord, what will happen to this man?"
22 Jesus said to him, "If I want him to remain [alive] until I return, what [business] is that of yours? You be my follower."
23 So, a rumor began circulating among the brothers that this disciple would not die. Yet Jesus did not tell him he would not die, but [He said], "If I want him to remain [alive] until I return, what [business] is that of yours?"