Exodus 30:12-14

12 a  “When you take the census of the people of Israel, then each shall give b  a ransom for his life to the  Lord when you number them, that there be no plague among them when you number them. 13Each one who is numbered in the census shall give this: half a shekel
A  shekel was about 2/5 ounce or 11 grams
according to the d  shekel of the sanctuary (the e  shekel is twenty gerahs),
A  gerah was about 1/50 ounce or 0.6 gram
g  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.
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