On Friday, everything is going to change. There will be accusations, denials, betrayals, and crucifixions. After the events of tomorrow, literally, nothing will be the same.
But today isn't Friday, it's Thursday and Jesus finds himself with his disciples for the last time. If you know what is going to happen tomorrow, what do you do? What do you say? How do you want those closest to you to remember you?
On this Thursday night, Jesus chooses to have a Passover meal with his disciples and at some point in the evening gets up from the table, puts on the clothes of a servant, and picks up a basin of water.
The son of God, on this not-so-ordinary Thursday, his last Thursday on earth, washes the feet of his disciples.