I’ve always thought that washing feet is an unfortunate cultural holdover from Jesus’ life. It’s beautiful and perfectly meaningful, but also super awkward in modern American culture. I never liked Maundy Thursday services for that reason! But it’s a perfect metaphor: feet get dirty really quickly, especially when wearing sandals. They stink. And they’re necessary to get us where we need to go. Washing feet was commonly what servants did for respected guests. It represents welcome. And, at the same time, it’s like a mini foot massage – it feels good, and it makes you feel refreshed and clean. So Jesus is offering to 1) take upon himself the role of a servant, 2) refresh and make clean his disciples, 3) welcome his disciples, and 4) humble himself to touch (literally) the lowest part of his disciples’ bodies.
Maybe Peter felt just as awkward about it as I do – he didn’t want to go through the foot washing either! He asked instead of Jesus to wash his whole body. But I think this verse contains the core of the story: if Jesus has washed us, we should be willing to wash others. Nothing is beneath us, because anyone whose feet we would wash is a child of God and worthy of being treated as such.