John 13:12 NKJV
[12] So when He had washed their feet, taken His garments, and sat down again, He said to them, "Do you know what I have done to you?
Jesus and his disciples's walked on dusty roads. It was customary for the lowest in rank to wash the feet the group after travel. Jesus was the highest in rank but he took the task of washing his disciples feet. Then he asked, do you know what I have done? The answer seemed obvious. But Jesus was telling them that beyond what they could physically see, he was doing something in the unseen realm. He was exemplifying humility. We must be conscious that our actions in the seen, or natural realm have implications in the unseen realm. So we must ask, "What am I doing? Not just what can be seen with the natural eye, but what am I doing that can only be seen in the spiritual realm?