And during supper Jesus, knowing that the Father had given all things into his hands, and that he had come from God and was going to God, got up from the table, took off his outer robe, and tied a towel around himself. Then he poured water into a basin and began to wash the disciples’ feet and to wipe them with the towel that was tied around him. He came to Simon Peter, who said to him, “Lord, are you going to wash my feet?” Jesus answered, “You do not know now what I am doing, but later you will understand.” Peter said to him, “You will never wash my feet.” Jesus answered, “Unless I wash you, you have no share with me.”
John 13
Giotto di Bondone, Washing of Feet, 1304-06. Cappella Scrovegni (Arena Chapel), Padua.
