Of all your gifts you shall offer up every heave offering due to the LORD, from all the best of them, the consecrated part of them.'
Numbers 18:29
Surrounding context
18:28 Thus you shall also offer a heave offering to the LORD from all your tithes which you receive from the children of Israel, and you shall give the LORD's heave offering from it to Aaron the priest.
18:29 Of all your gifts you shall offer up every heave offering due to the LORD, from all the best of them, the consecrated part of them.'
18:30 Therefore you shall say to them: "When you have lifted up the best of it, then the rest shall be accounted to the Levites as the produce of the threshing floor and as the produce of the winepress.