Exodus 30:11-21

And Jehovah spake unto Moses, saying, When thou takest the sum of the children of Israel, according to those that are numbered of them, then shall they give every man a ransom for his soul unto Jehovah, when thou numberest them; that there be no plague among them, when thou numberest them. This they shall give, every one that passeth over unto them that are numbered, half a shekel after the shekel of the sanctuary; (the shekel is twenty gerahs), half a shekel for an offering to Jehovah. Every one that passeth over unto them that are numbered, from twenty years old and upward, shall give the offering of Jehovah. The rich shall not give more, and the poor shall not give less, than the half shekel, when they give the offering of Jehovah, to make atonement for your souls. And thou shalt take the atonement money from the children of Israel, and shalt appoint it for the service of the tent of meeting; that it may be a memorial for the children of Israel before Jehovah, to make atonement for your souls. And Jehovah spake unto Moses, saying, Thou shalt also make a laver of brass, and the base thereof of brass, whereat to wash. And thou shalt put it between the tent of meeting and the altar, and thou shalt put water therein. And Aaron and his sons shall wash their hands and their feet thereat: when they go into the tent of meeting, they shall wash with water, that they die not; or when they come near to the altar to minister, to burn an offering made by fire unto Jehovah. So they shall wash their hands and their feet, that they die not: and it shall be a statute for ever to them, even to him and to his seed throughout their generations.