Exodus 30:11-21

Then the LORD said to Moses, “Whenever you take a census of the people of Israel, each man who is counted must pay a ransom for himself to the LORD. Then no plague will strike the people as you count them. Each person who is counted must give a small piece of silver as a sacred offering to the LORD. (This payment is half a shekel, based on the sanctuary shekel, which equals twenty gerahs.) All who have reached their twentieth birthday must give this sacred offering to the LORD. When this offering is given to the LORD to purify your lives, making you right with him, the rich must not give more than the specified amount, and the poor must not give less. Receive this ransom money from the Israelites, and use it for the care of the Tabernacle. It will bring the Israelites to the LORD’s attention, and it will purify your lives.” Then the LORD said to Moses, “Make a bronze washbasin with a bronze stand. Place it between the Tabernacle and the altar, and fill it with water. Aaron and his sons will wash their hands and feet there. 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! 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.”