Jesus puts his garments back on, returns to the meal, and asks whether the disciples understand what he has done. He accepts their titles 'Master' and 'Lord' and then makes those titles the basis of his command.
Because the superior has washed feet, the disciples ought to wash one another's feet.
Ancient households were sharply structured by status. A servant was not greater than the master, and a messenger was not greater than the one who sent him. Jesus does not abolish the fact of his authority; he reasons from it. The Greek word translated 'example' means a pattern or model to be followed. Christians have differed over whether the command establishes literal foot washing as an ordinance in every setting or primarily requires the servant posture embodied by the act.
The social hierarchy gives Jesus' reasoning its force. No disciple can appeal to dignity, rank, or leadership as a reason to avoid lowly service when the Lord himself has taken the lower place.
The episode therefore redefines greatness without denying Jesus' lordship: his authority supplies the pattern for self-giving service.