Deuteronomy 18:3-9

And this shall be the priests’ due from the people, from those offering a sacrifice, whether an ox or a sheep: they shall give to the priest the shoulder and the two cheeks and the stomach. The firstfruits of your grain, of your wine and of your oil, and the first fleece of your sheep, you shall give him. For the LORD your God has chosen him out of all your tribes to stand and minister in the name of the LORD, him and his sons for all time. “And if a Levite comes from any of your towns out of all Israel, where he lives—and he may come when he desires—to the place that the LORD will choose, and ministers in the name of the LORD his God, like all his fellow Levites who stand to minister there before the LORD, then he may have equal portions to eat, besides what he receives from the sale of his patrimony. “When you come into the land that the LORD your God is giving you, you shall not learn to follow the abominable practices of those nations.