Numbers 31:28-30, 47

“Then tax the spoils that go to the soldiers at the rate of one life out of five hundred, whether humans, cattle, donkeys, or sheep. It’s a GOD-tax taken from their half-share to be turned over to Eleazar the priest on behalf of GOD. Tax the congregation’s half-share at the rate of one life out of fifty, whether persons, cattle, donkeys, sheep, goats, or other animals. Give this to the Levites who are in charge of the care of GOD’s Dwelling.”

From the half-share going to the People of Israel, Moses, just as GOD had instructed him, picked one out of every fifty persons and animals and gave them to the Levites, who were in charge of maintaining GOD’s Dwelling.