Inheritance
God promised Aaron, the first Kohen and his decendents several honourable duties and inheritances: 

Exodus 40:15 God promised: "An everlasting priesthood throughout their generations." 

Numbers 8:19 God promised: "I have given the Levites - They are given to Aaron and to his sons from among the children of Israel, to do the service of the children of Israel in the tent of meeting, and to make atonement for the children of Israel"  

Numbers 18,1 "The LORD said unto Aaron: Thou and thy sons and thy fathers house with thee shall bear the iniquity of the sanctuary; and thou and thy sons with thee shall bear the iniquity of your priesthood."

Numbers 18:5 God commanded Aaron: "Ye shall keep the charge of the holy things, and the charge of the altar that there be wrath no more upon the children of Israel."

Numbers 18:20 God promised: "Thou shalt have no inheritance in their land, neither shalt thou have any portion among them; I am thy portion and thine inheritance among the children of Israel."

Deuteronomy 10:9 God promised Aaron: "Wherefore Levi hath no portion nor inheritance with his brethren; the LORD is his inheritance."

Deuteronomy 18:1 God promised: "The priests the Levites, even all the tribe of Levi, shall have no portion nor inheritance with Israel; they shall eat the offerings of the LORD made by fire, and His inheritance and they shall have no inheritance among their brethren; the LORD is their inheritance."

Deuteronomy 31:25: "Moses commanded the Levites, that bore the ark of the covenant of the LORD, saying: Take this book of the law, and put it by the side of the ark of the covenant of the LORD your God, that it may be there for a witness against thee."

Enjoy fruitcake