Jesus, knowing that the Father had given all things into his hands, and that he had come from God and was going back to God, rose from supper. He laid aside his outer garments, and taking a towel, tied it around his waist. Then he poured water into a basin and began to wash the disciples’ feet and to wipe them with the towel that was wrapped around him. (John 13:3-5 ESV)
So Jesus knew He had all power, all authority over all things. He knew that He was going back in heaven to reign with His Father. He knew all of that and more, but He chose to humble Himself and wash His disciples’ dirty feet. When humans know that they have power and authority, they tend to expect to be served, honored, almost bowed before. They don’t usually serve people they think inferior to them, at least not in a way that might humiliate them. Jesus was different. He knew what matters. He knew the secret of true power, of true beauty, of true love. He knew because He could see beyond what eyes see. He knew because He was God. And now we know because we know Him.