Numbers 31:27

You shall wash your clothes on the seventh day, and you shall be clean. Afterward you shall come into the camp.”

The LORD spoke to Moses, saying,

“Count the plunder that was taken, both of man and of animal, you, and Eleazar the priest, and the heads of the fathers’ households of the congregation;

Levy a tribute to the LORD of the men of war who went out to battle: one soul of five hundred; of the persons, of the cattle, of the donkeys, and of the flocks.

Take it from their half, and give it to Eleazar the priest, for the LORD’s wave offering.

Of the children of Israel’s half, you shall take one drawn out of every fifty, of the persons, of the cattle, of the donkeys, and of the flocks, of all the livestock, and give them to the Levites, who perform the duty of the LORD’s tabernacle.”