Origen
Catena Aurea · Johannesevangelium 13
Then cometh he to Simon Peter: and Peter said unto him, Lord, dost thou wash my feet? Jesus answered and said unto him, What I do thou knowest not now; but thou shalt know hereafter. Peter saith unto him, Thou shalt never wash my feet. Jesus answered him, If I wash thee not, thou hast no part with me. Simon Peter saith unto him, Lord, not my feet only, but also my hands and my head. Jesus saith to him, He that is washed needeth not save to wash his feet, but is clean every whit: and ye are clean, but not all. For he knew who should betray him; therefore said he, Ye are not all clean. Jesus answered and said unto him, What I do thou knowest not now; but thou shalt know hereafter.
Let those who refuse to allegorize these and like passages, say how it is probable that he who out of reverence for Jesus said, Thou shalt never wash my feet, would have had no part with the Son of God; as if not having his feet washed was a deadly wickedness. Wherefore it is our feet, i. e. the affections of our mind, that are to be given up to Jesus to be washed, that our feet may be beautiful; especially if we emulate higher gifts, and wish to be numbered with those who preach glad tidings.