“He began to wash the disciples' feet”
So He got up from the supper, laid aside His outer garments, and wrapped a towel around His waist. After that, He poured water into a basin and began to wash the disciples' feet and dry them with the towel that was around Him. (John 13:3–15 BSB)
What it sounds like today
A humble gesture; church foot-washing services have made it feel ceremonial.
The cultural key
Roads were dust, dung, and refuse; sandaled feet at dinner were genuinely foul. Washing a guest's feet was the job of the lowest slave in the household, and Jewish tradition held it too degrading to require even of a Jewish slave: it was Gentile slaves' work (compare the sandal saying at Mark 1:7). No one at this supper had done it, and Luke records the disciples arguing that very evening about which of them was greatest. Jesus strips to the waist-cloth (a slave's working dress) and goes around the circle, including the feet of Judas, whose betrayal John has just announced. Peter's horror is the correct cultural reading: this is upside down.
Recovered meaning
The teacher performs the one task judged beneath every free person in the room, on the eve of doing its cosmic equivalent. Then the assignment: 'you also ought to wash one another's feet.' Rank in this kingdom is measured with a towel.