Exodus 30:11-16

11Then Adonai spoke to Moses saying,

12“When you tally the sum of Bnei-Yisrael by numbering them, then every man must pay a ransom for his soul to Adonai when you count them, so that no plague will fall on them.

13Everyone among them who crosses over must give half a shekel according to the Sanctuary shekel (which is 20 gerahs): half a shekel as an offering to Adonai.

14Everyone who crosses over among them who is counted, from 20 years old and upward, is to give the offering to Adonai.

15The rich are not to give more and the poor are not to give less than the half shekel, when they present the offering of Adonai to make atonement for your souls.

16You are to take the atonement money from Bnei-Yisrael and give it for the service of the Tent of Meeting, so that it may be a memorial for Bnei-Yisrael before Adonai, to make atonement for your souls.”