For all the righteous possess the sacerdotal rank. And all the apostles of the Lord are priests, who do inherit here neither lands nor houses, but serve God and the altar continually. Of whom Moses also says in Deuteronomy, when blessing Levi, "Who said unto his father and to his mother, I have not known thee; neither did he acknowledge his brethren, and he disinherited his own sons: he kept Thy commandments, and observed Thy covenant." But who are they that have left father and mother, and have said adieu to all their neighbours, on account of the word of God and His covenant, unless the disciples of the Lord? Of whom again Moses says, "They shall have no inheritance, for the Lord Himself is their inheritance." And again, "The priests the Levites shall have no part in the whole tribe of Levi, nor substance with Israel; their substance is the offerings (fructifications) of the Lord: these shall they eat." Wherefore also Paul says, "I do not seek after a gift, but I seek after fruit."
Source: Against Heresies Book IV