This evening, in a Bible study with some friends, we read:
Now before the Feast of the Passover, when Jesus knew that his hour had come to depart out of this world to the Father, having loved his own who were in the world, he loved them to the end. During supper, when the devil had already put it 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 had come from God and was going back to God, rose from supper. He laid aside his outer garments, and taking a towel, tied it around his waist. Then he poured water into a basin and began to wash the disciples’ feet and to wipe them with the towel that was wrapped around him.
John is not explicit about it, but an image of Christ’s coming sacrifice for sin is hidden in the Upper Room foot washing. As he goes round the table, washing each of the disciples, he wipes the dust and grime from each of them onto the towel tied around him as a garment. When he has finished, he stands before them. On his garment he wears their filth, and thus foreshadows the cross. By contrast the disciples, though uncomfortable with the action of Christ, are reclined leisurely, freshly washed and prepared to partake of the Passover Feast.