Numbers 15:18-21

18“Speak to the Israelites and say to them: ‘When you enter the land to which I am taking you 19and you eat the food of the land, present a portion as an offering to the LORD . 20Present a loaf from the first of your ground meal and present it as an offering from the threshing floor.

21Throughout the generations to come you are to give this offering to the LORD from the first of your ground meal.