In reading through the beginnings of the wanderings of the Israelites, there is a beautiful concept that rises up in the instructions concerning Aaron, the priest. God instructed that a wash basin be built and placed between the altar of sacrifice and the entrance to the holy place where only the priests could go. Before Aaron became the high priest he was to be consecrated. His whole body had to be washed from the water in the basin.
17 Then the Lord said to Moses, 18 “Make a bronze washbasin with a bronze stand. Place it between the Tabernacle and the altar, and fill it with water. 19 Aaron and his sons will wash their hands and feet there. 20 They must wash with water whenever they go into the Tabernacle to appear before the Lord and when they approach the altar to burn up their special gifts to the Lord—or they will die! 21 They must always wash their hands and feet, or they will die. This is a permanent law for Aaron and his descendants, to be observed from generation to generation.”
Once that was accomplished he was ready for service to God on behalf of the people. However, every time after he only had to wash his hands and feet. His hands represented the things he had done and his feet for the places he had gone. Before he could approach God he needed to offer a sacrifice for sin and then wash his hands and feet.
Jesus Christ is the once-for-all sacrifice for all of humanity. When we come to realize our need for God and the overwhelming barrier of our sin we see Jesus. We accept Jesus’ death as the required sacrifice for our sin. We only need to do this once. Whenever we wish to approach God thereafter we must confess (wash) our hands (things we’ve done and said) and feet (places we have gone).