Numbers 31:29-31

take it from their half, and give it to Eleazar the priest as a heave offering to the LORD. And from the children of Israel’s half you shall take one of every fifty, drawn from the persons, the cattle, the donkeys, and the sheep, from all the livestock, and give them to the Levites who keep charge of the tabernacle of the LORD.” So Moses and Eleazar the priest did as the LORD commanded Moses.