John 21:20-22

20Peter turned and saw the disciple whom Jesus loved following them, the one who also had leaned back against him during the supper and had said, "Lord, who is it that is going to betray you?"

21When Peter saw him, he said to Jesus, "Lord, what about this man?"

22Jesus said to him, "If it is my will that he remain until I come, what is that to you? You follow me!"