Numbers 15:20

15:20 You must offer up a cake of the first of your finely ground flour as a raised offering; as you offer the raised offering of the threshing floor, so you must offer it up.

Numbers 18:30

18:30 “Therefore you will say to them, ‘When you offer up the best of it, then it will be credited to the Levites as the product of the threshing floor and as the product of the winepress.