Numbers 18:28-30

New Century Version

²⁸ In this way you will present an offering to the Lord as the other Israelites do. When you receive a tenth from the Israelites, you will give a tenth of that to Aaron, the priest, as the Lord’s share. ²⁹ Choose the best and holiest part from what you are given as the portion you must give to the Lord.’

³⁰ “Say to the Levites: ‘When you present the best, it will be accepted as much as the grain and wine from the other people.