John 13 begins the long Upper Room section, Jesus' final teaching before the cross. John writes, Having loved his own who were in the world, he loved them to the end. Knowing that the Father had given all things into His hands, Jesus did something shocking. He laid aside His garments, took a towel, and washed His disciples' feet. In that culture, this was a task for a servant. This act pictured what Jesus came to do: the Son of God humbled Himself to make sinners clean, as Philippians 2 describes.
Peter refused at first, then asked to be washed all over. Jesus explained that someone who has bathed only needs his feet washed. Those who belong to Him are cleansed, though they still need daily cleansing from sin. Then Jesus said, I have given you an example, that you should also do as I have done to you. True greatness in God's kingdom is humble service.
Jesus washed His friends' feet, knowing one would betray Him. Troubled in spirit, Jesus identified the betrayer by giving him a piece of bread. Judas left, and it was night, both outside and in his heart. Then Jesus spoke of His glory and gave a new commandment. Love one another; just like I have loved you, you also love one another. The newness is in the standard: as I have loved you. This love would mark His followers before the world. When Peter vowed loyalty, Jesus foretold his threefold denial. Even so, Jesus' love for Peter would not fail.