Bear the responsibility for offenses connected with the priesthood

Numbers 18:1-19
The Lord said to Aaron,"You, your sons and your family are to bear the responsibility for offenses connected with the sanctuary, and you and your sons alone are to bear the responsibility for offenses connected with the priesthood.
Only you and your sons may serve as priests in connection with everything at the altar and inside the curtain. I am giving you the service of the priesthood as a gift. Anyone else who comes near the sanctuary is to be put to death.
All the holy offerings the Israelites give me I give to you and your sons as your portion, your perpetual share. You are to have the part of the most holy offerings that is kept from the fire. “I give you all the finest olive oil and all the finest new wine and grainthey give the Lord as the firstfruits of their harvest.  All the land’s firstfruits that they bring to the Lord will be yours. Everyone in your household who is ceremonially clean may eat it.
But you must not redeem the firstborn of a cow, a sheep or a goat; they are holy. Splash their blood against the altar and burn their fat as a food offering, an aroma pleasing to the Lord.
Neither priests nor Levites share in the inheritance of the land" God is their share. Instead, God gives the priests the remainder of all the sacrificial offerings, firstfruits and firsttlings.
Why?
Aaron and his sons are servant of the Lord, so they have not land and business, but only serve the Lord with priesthood. God takes care their living and gives them  the offering from Israelite.
Not only meal but also olive oil, grain and all first fruits. So Levites do not worry their living problem, God will supports them.
God also gives them the regulation to serve Him.
Even now minister and pastor will be support by the Christians, for they are the servant of the Lord.
How?
Take care the living of God's servant, they are the chosen one like Aaron and his sons.