John's account of the Last Supper does not report the institution of the Eucharist but does include a foot-washing during the meal, an action which has no precedent in any Judaic meal-ritual of this time! What does it mean?
In the Mediterranean world, people communicate both in word and in deed. In this culture, actions often speak louder than words. This particular washing of the feet is clearly understood in the culture as a “symbolic action,” that is, a deed that not only represents reality but effectively sets it in motion or a deed that propels an already initiated event still further forward toward completion. Prophets like Jeremiah (e.g., Jer 13:1-11) and Ezekiel (e.g., Ez 4) performed symbolic actions which to non-Mediterranean people look very much like bizarre behavior.
Notice that Jesus performs his symbolic action after the devil convinces Judas to betray Jesus (Jn 13:2). The devil tests Judas’ loyalty to Jesus, and sadly Judas yields and proves disloyal (Jn 13:27). Jesus’ symbolic action thus further propels forward toward completion an event, namely, Jesus' death, which has already been initiated by Judas’ willingness to betray Jesus.
Jesus' symbolic action receives two interpretations in the text (Jn 13:1-11; 13:12-20). In the first interpretation, the allusions to Jesus' approaching death in verses 1-3 indicate that Jesus' washing of the disciples' feet, on one level, signifies his humiliating death on their behalf (see Jn 10:11, 15; 18:12-14). Verse 10 makes it even clearer, especially if the phrase "except for the feet" could be omitted in this lectionary reading as it is in ancient manuscripts and in the New Jerusalem Bible translation. Then the “bathing” would implicitly refer to the foot-washing, and the reader or listener can understand why Jesus rejects Peter's request for additional washings (head and hands), or washing of the entire body.
On another level, the washing of the feet points to another symbolism. Streets in antiquity were filled with human and animal waste. A person walking the streets inevitably had soiled and smelly feet. Washing the feet of guests was usually a task for slaves or low status servants. That Jesus would do this stuns his disciples, mainly because they are missing his intended symbolic meaning, which is more than humility.
In biblical times people considered the hands and feet as a zone of the human body symbolizing human activity. To wash the feet (or hands) is to wash away the offensive deeds performed by these appendages. Foot-washing is therefore equivalent to forgiveness. When Jesus urges them to repeat this action, he is not urging them to wash feet but rather to forgive each other as he forgives them. The end result of such mutual forgiveness, of course, is greater group cohesion and solidarity. This, in fact, is what Jesus is building here.
Verses 12-20 explicitly state the second interpretation of the foot-washing which is already implied in the preceding verses (hands-feet zone). Jesus gives his disciples an example to imitate among one another. They are to forgive one another and create strong bonds of fellowship. (1 Tim 5:10 indicates how seriously this example was followed particularly by widows.) This interpretation receives fuller explanation in Jn 15:23-13 where loving one another includes willingness to lay down life for one another. Thus foot-washing even in this second interpretation retains a relationship with the death of Jesus and the community that he strengthened on the night before he died.
In the Middle-east, unrelated people rarely if ever eat together. Meals are shared only with relatives. A stranger taken into a Mediterranean family temporarily is also temporarily transformed into a friend in order to be able to share the family meal. But groups in the Middle-east, such as the Twelve, are surrogate-kinship groups—that is, they are just like family. Thus Jesus' symbolic action of foot-washing and its obvious (to those original viewers) reference to his death, to forgiveness, and to group cohesion would not be lost on the disciples. Eating a meal with Jesus renders one a family-member, and family-members willingly sacrifice for other family members.