John 21:19-24

This He spoke, signifying by what death he would glorify God. And when He had spoken this, He said to him, “Follow Me.” Then Peter, turning around, saw the disciple whom Jesus loved following, who also had leaned on His breast at the supper, and said, “Lord, who is the one who betrays You?” Peter, seeing him, said to Jesus, “But Lord, what about this man?” Jesus said to him, “If I will that he remain till I come, what is that to you? You follow Me.” Then this saying went out among the brethren that this disciple would not die. Yet Jesus did not say to him that he would not die, but, “If I will that he remain till I come, what is that to you?” This is the disciple who testifies of these things, and wrote these things; and we know that his testimony is true.