John 21: 15 - 19
15 When they had finished breakfast, Jesus said to Simon Peter, "Simon, son of John, do you love me more than these?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Feed my lambs."
16 A second time he said to him, "Simon, son of John, do you love me?" He said to him, "Yes, Lord; you know that I love you." He said to him, "Tend my sheep."
17 He said to him the third time, "Simon, son of John, do you love me?" Peter was grieved because he said to him the third time, "Do you love me?" And he said to him, "Lord, you know everything; you know that I love you." Jesus said to him, "Feed my sheep.
18 Truly, truly, I say to you, when you were young, you girded yourself and walked where you would; but when you are old, you will stretch out your hands, and another will gird you and carry you where you do not wish to go."
19 (This he said to show by what death he was to glorify God.) And after this he said to him, "Follow me."

EWTN