Here Jesus begins to speak about "washing" to mean making someone spiritually clean or pure. Since Jesus said in 13:7 that the disciples would not fully understand what was happening, translations should keep the "washing" imagery and not try to explain it in the text.
It can be stated explicitly that Jesus is talking about washing feet. Alternate translation: "If I do not wash your feet" ([[rc://en/ta/man/translate/figs-explicit]])
# you have no share with me
The word "share" means a part of an inheritance. Here it is a metaphor meaning that Peter would not have fellowship or anything in common with Jesus. Alternate translation: "you will not be my disciple" or "you will not belong to me" (See: [[rc://en/ta/man/translate/figs-metaphor]])