"For I received from the Lord what I also passed on to you, that the Lord Jesus on the night in which he was betrayed took off his outer robe and bent down to serve, washing his disciples feet he said, “This is my body, which is for you. Do this in remembrance of me.” - 1 Cor 11:13 (with liberties)John tells the story of Jesus washing the disciples' feet, in about the same place in the storyline where the others tell about the institution of the Lord's supper. I find it interesting that John doesn't mention the actual passover meal at all, and yet details a good portion of the dialouge in much greater detail than the other writers. By conclusion I figure the feet washing affected him more profoundly than it did Matthew, who by profession we know was a wealthy educated Jew. Matthew was caught up by the now realized fulfillment of the Passover meal. The son of thunder was caught up by the master choosing to be the slave.
John has come a long way in his life from the "son of thunder" we meet at the beginning of his life with Jesus, to the aged saint and elder of the church who writes 1 John, the epistle of love. I wonder how profoundly this act has much to do with that.
I have read authors point out that the feet washing instruction Jesus gives is about service within the family God. This is not to say that Jesus did not want the church to serve those outside the "church", since he makes that clear in many other place. However this act, this is about how the people of God treat each other.
I get the idea when John writes, "whoever has stuff and sees his brother in need without caring, how can he call himself a lover of God" (1 John 3:17 paraphrased) he is thinking back to this example Jesus set.
For John, in the entirety of his writing, we see that love for one another actualized through service to one another, is a sacramental act. For John, having his feet washed was a saving moment.
Holy Week Prayer: Lord Father, remind me constantly that loving my brother, through actual sacrificial service on my part, is an act of sacrament in your Kingdom.
An Observation on John 13:1-17