Num Numbers, chapter Book of Numbers, chapter 18
You shall redeem those who are to be redeemed of them from a month old, according to your estimation, for five shekels of money, according to the shekel18:16 A shekel is about 10 grams or about 0.35 ounces. of the sanctuary, which weighs twenty gerahs.18:16 A gerah is about 0.5 grams or about 7.7 grains.Exo 30:13; Lev 27:25; Num 3:47; Ezk 45:12