John 13:6-8 NIV

6 He came to Simon Peter, who said to him, "Lord, are you going to wash my feet?"
7 Jesus replied, "You do not realize now what I am doing, but later you will understand."1

References for John 13:7

      8 "No," said Peter, "you shall never wash my feet." Jesus answered, "Unless I wash you, you have no part with me."