Augustine of Hippo
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.
(Tr. lvi. 4) Clean all except the feet. The whole of a man is washed in baptism, not excepting his feet; but living in the world afterwards, we tread upon the earth. Those human affections then, without which we cannot live in this world, are, as it were, our feet, which connect us with human things, so that ifwe say we have no sin, we deceive ourselves. (1 John 1:8) But if we confess our sins, He who washed the disciples’ feet, forgives us our sins even down to our feet, wherewith we hold our converse with earth.