Question: "What does the Bible say about foot-washing?"
Answer: The dusty and dirty conditions of the region necessitated the need for foot-washing. Although the disciples most likely would have been happy to wash Jesus' feet, they could not conceive of washing each other's feet. This was because in the society of the time foot-washing was reserved for the lowliest of menial servants. Peers did not wash one another's feet, except very rarely and as a mark of great love. Luke points out (22:24) that they were arguing about who was the greatest of them, so that none was willing to stoop to wash feet. When Jesus moved to wash their feet (see also John 13:1-16), they were shocked. His actions serve also as symbolic of spiritual cleansing (vs. 6-9) and a model of Christian humility (vs. 12-17). Through this action Jesus taught the lesson of selfless service that was supremely exemplified by His death on the cross.
The foot-washing was an example, a pattern. Many groups throughout church history have practiced literal foot-washing as a church ordinance. However, present culture in many lands does not call for the need to wash dust from the feet of one's guests. Whereas the Lord's Supper was practiced by the early church, it apparently did not practice foot-washing as an ordinance in church gatherings. This passage emphasizes inner humility, not a physical rite. A Christian widow's practice of "washing the feet of the saints" (I Timothy 5:10) speaks not of her involvement in a church ordinance but of her humble slave-like service to other believers. Not to follow the example of Jesus is to exalt oneself above Him and to live in pride. “No servant is greater than his master” (cf. John 12:26).