After he poured water into a basin and began to wash the disciples’ feet, and to wipe them with the towel with which he was girded, then comes he to Simon Peter. And Peter says unto him, Lord, do you wash my feet? Jesus answered and said unto him, What I do, you do not know now, but you shall know hereafter. Peter says unto him, You do not need to wash my feet. Jesus answered him, If I wash you not, you have no part with me. Simon Peter says unto him, Lord, not my feet only, but also my hands and my head. Jesus says to him, He that has washed his hands and his head needs not save to wash his feet, but is clean every whit. And you are clean, but not all. Now this was the custom of the Jews under their law; wherefore, Jesus did this that the law might be fulfilled, for he knew who should betray him. Therefore said he, you are not all clean.

John 9:2