John does not record Jesus' last supper. At the place where the supper occurs in the other Gospels, John offers this story with its commandment to love others as Christ has loved us, a humility and love demonstrated through foot washing. The early church practiced foot washing to follow Jesus' example of humble service. We hear nothing about ceremonial foot washing in liturgy, however, until Augustine. A seventh century Spanish liturgy was the first to use it on Maundy Thursday.
Lutheran congregations have the choice to use it on that day as well.
When we do, we quickly recognize the many meanings feet have for us. We consider them sensitive and silly appendages. People don't want to expose them. Feet get knobby and worn. They are covered with protruding veins, bunions and calluses.