Numbers 18:25-32 - Instructions For The Levites
25 Jehovah said to Moses: 26 Speak to the Levites and say to them: 'You will take one-tenth of the Israelites' income that I am giving you as your property. When you do, you must contribute one-tenth of that income as your contribution to Jehovah. 27 Your contribution will be considered to be grain from the threshing floor or juice from the winepress. 28 You will also contribute one-tenth of your income to Jehovah out of all that you receive from the Israelites' income. You will give Jehovah's contribution to the priest Aaron. 29 Out of all the gifts you receive, you must contribute the best and holiest parts to Jehovah.'
30 Also tell them: 'When you contribute the best part, your contribution will be considered to be produce from the threshing floor or winepress. 31 You and your households may eat it anywhere. This is because it is the wages you receive for your work at the tent of meeting. 32 When you contribute the best part, you will not suffer the consequences of any sin. You will not be dishonoring the holy offerings given by the Israelites, and you will not die.'