Numbers.
Chapter 18.
The Lord told Aaron, “You and your sons and the other Levites bear the responsibility for sins relating to the sanctuary. You and your sons alone bear the responsibility for sins relating to your priesthood. 
Have your brothers from the tribe of Levi, your father's tribe, join you to help you and your sons with your service in the Tent of the Testimony. 
They will take care of your responsibilities and those relating to the Tent, but they must not come too close to the sacred objects of the sanctuary or the altar, otherwise they will die, and you will too. 
They are to help you and take care of the responsibilities of the Tent of Meeting, doing all the work at the Tent, but they are not allowed to be with you during your priestly ministry. 
You are to carry out the responsibilities relating to the sanctuary and the altar, so that my anger will not fall on the Israelites again. 
Look, I myself have chosen your brothers the Levites from the Israelites as my gift to you, dedicated to the Lord to do the work that relates the Tent of Meeting. 
But only you and your sons are responsible for your priesthood, doing all that concerns the altar and is behind the veil. Only you are to perform that service. I am giving you the gift of your priesthood, but anyone else who approaches the sanctuary must be executed.” 
The Lord told Aaron, “Listen, I have put you in charge of officiating at my offerings. All the holy contributions of the Israelites that they bring are reserved for you, and this is a permanent rule. 
Part of the most holy offerings taken from the burnt offerings are yours. Part of all the offerings they give me as most holy offerings, whether it's grain offerings or sin offerings or guilt offerings, that part belongs to you and your sons. 
You shall eat it in a most holy place. Every male is allowed to eat it. You are to regard it as something holy. 
The following also belongs to you: the voluntary gifts as well as all the wave offerings of the Israelites. I have given this to you and your sons and daughters as a permanent rule. Everyone in your household who is ceremonially clean is allowed to eat it. 
I am giving you all the best olive oil and all the best new wine and grain that the Israelites give as firstfruits to the Lord. 
The firstfruits of all the crops they produce in their land that they bring to the Lord are yours. Everyone in your family who is ceremonially clean is allowed to eat them. 
Everything in Israel that is dedicated to the Lord is yours. 
Every firstborn, whether human or animal, that is offered to the Lord is yours. But you must buy back every firstborn son and every firstborn male of unclean animals. 
When they are one month old you shall pay the redemption price of five shekels of silver, (using the sanctuary shekel standard), equivalent to twenty gerahs. 
But you are not allowed to redeem the firstborn of an ox, a sheep, or a goat because they are holy. You shall sprinkle their blood on the altar, and burn their fat as a burnt offering accepted by the Lord. 
Their meat is yours, in the same way that the breast and right thigh of the wave offering are yours. 
I am giving all the voluntary gifts that the Israelites present to the Lord to you and to your sons and daughters as a permanent rule. It is a permanent agreement of salt before the Lord for you and your descendants.” 
“You won't possess property in their country, and you won't have a share in their land. I am your share and your possession among the Israelites. 
Instead I have given the Levites all the tithes in Israel as compensation for the service they provide in doing the work in the Tent of Meeting. 
The Israelites are no longer allowed to approach the Tent of Meeting, or they will commit an offense and die. 
The Levites are to carry out the work in the Tent of Meeting, and they must take responsibility for any sins involved. This is a permanent rule for all future generations. The Levites won't receive a share of land among the Israelites. 
Instead I have given to the Levites as their compensation the tithe that the Israelites give to the Lord as a contribution. That's why I told them that they wouldn't receive a share of land among the Israelites.” 
The Lord told Moses, 
“Talk to the Levites and explain to them, ‘When you receive from the Israelites the tithe that I have given you as your compensation, you must return part of it as an offering to the Lord: a tithe of the tithe. 
Your offering will be considered as if it were the firstfruits of grain from your threshing floor or grape juice from the winepress. 
In this way you are to contribute an offering to the Lord from every tithe you receive from the Israelites, giving the Lord's offering to Aaron the priest. 
From all the gifts you receive you are to contribute as the Lord's offering the very best, the holiest part of every gift.’ 
So tell the Levites, ‘When you have presented the best part, it will be considered as your contribution produced by your threshing floor or winepress. 
You and your families may eat it anywhere because it's compensation for your service in the Tent of Meeting. 
You will not be considered to have sinned if you have presented the best part of it. But if you treat the sacred offerings of the Israelites with disrespect you will die.’” 
