The Lord washed their feet of the disciples -
Christ.
If I have washed your feet, who am your Lord and Master, ye shall wash one another's feet among you. Hereby have I given you a reproof and an example; as I did unto him, so shall ye do unto him. Verily, verily, I say unto you, the servant is no more than his lord; neither is the sent messenger more than he that sent him. Do you know this? Blessed are you if you do. Joh. 13, 14-17.