John 13:2-5, 12-14

And during supper, the devil having already put into the heart of Judas Iscariot, Simon’s son, to betray him, Jesus, knowing that the Father had given all things into his hands, and that he came forth from God, and goeth unto God, riseth from supper, and layeth aside his garments; and he took a towel, and girded himself. Then he poureth water into the basin, and began to wash the disciples’ feet, and to wipe them with the towel wherewith he was girded.

So when he had washed their feet, and taken his garments, and sat down again, he said unto them, Know ye what I have done to you? Ye call me, Teacher, and, Lord: and ye say well; for so I am. If I then, the Lord and the Teacher, have washed your feet, ye also ought to wash one another’s feet.