Charles Spurgeon Commentary John 13:7-8

"Jesus answered and said unto him, What I do thou knowest not now; but thou shalt understand 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." — John 13:7-8 (ASV)

Jesus answered and said to him, What I do you do not know now, but you shall know afterward. Peter said to him, You shall never wash my feet.

That is, "Never, as long as I live, shall you do such a thing as that."