John Wesley on John 13:14

Ye ought also to wash one another's feet - And why did they not? Why do we not read of any one apostle ever washing the feet of any other? Because they understood the Lord better. They knew he never designed that this should be literally taken. He designed to teach them the great lesson of humble love, as well as to confer inward purity upon them. And hereby he teaches us, In every possible way to assist each other in attaining that purity; To wash each other's feet, by performing all sorts of good offices to each other, even those of the lowest kind, when opportunity serves, and the necessity of any calls for them.