Then Peter, turning around, saw a disciple following. This was the disciple whom Jesus loved, the one who had also leaned on Jesus’ breast at the supper and asked, “Lord, who is going to betray You?” Peter seeing him, said to Jesus, “Lord, what about this man?” Jesus said to him, “If I desire that he stay until I come, what is that to you? You follow me.” This saying therefore went out among the brothers, that this disciple wouldn’t die. Yet Jesus didn’t say to him that he wouldn’t die, but, “If I desire that he stay until I come, what is that to you?” This is the disciple who testifies about these things, and wrote these things. We know that his witness is true. There are also many other things which Jesus did, which if they would all be written, I suppose that even the world itself wouldn’t have room for the books that would be written.
(Joh 21:20-25 WEB)