Washing of the feet falls under the host's task, often done by the slaves of the household. Among the disciples, none of them took the duty of washing the feet of the others, so Jesus stood up and did it. The disciples showed great insensitivity while Jesus showed great servanthood.
Jesus washed the disciples' feet. This scenario is unusual since teachers normally do not serve his students. Jesus' servanthood has no demarcation line or position. Notaly, Jewish Israelite slaves never have to wash feet being Abraham's descendants.
Jesus served Peter even if the latter didn't understand why. Jesus chooses to serve and love anyway.
Jesus washed 12 pairs of feet, one pair even belonging to the enemy--Judas. Jesus did not seem to have a rational demarcation despite of what He already knew. Jesus kept serving anyway.
Normal death sentence convicts have a last supper and last wish, sort of to show them a final glimpse of enjoyment before they are bound to die. Jesus did the contrary--continually serving even until His death, to the very end. For Jesus, everytime is a time to serve the LORD.
*based on John 13:1-5
bt Rev. Dr. David Cheung