Exodus 30:13-16

13Each one who is numbered in the census shall give this: half a shekel according to the shekel of the sanctuary (the shekel is twenty gerahs), half a shekel as an offering to the Lord.

14Everyone who is numbered in the census, from twenty years old and upward, shall give the Lord's offering.

15The rich shall not give more, and the poor shall not give less, than the half shekel, when you give the Lord's offering to make atonement for your lives.

16You shall take the atonement money from the people of Israel and shall give it for the service of the tent of meeting, that it may bring the people of Israel to remembrance before the Lord, so as to make atonement for your lives."