There is a significant transition that takes place here in this chapter in regards to who is in charge of the temple of the Lord. While in the past it was the Levites, the house of Levi, who had charge over the temple, this chapter shows a significant change. Now it is the house of Zadok, also from the Levites, who are to take charge over the temple. It is interesting that Ezekiel himself comes from that lineage, and so in many ways this was very self-benefitting for Ezekiel. Where does Zadok point to for his ancestry? Zadok was the priest who took over charge of the temple, or become the chief priest, under Solomon when he replaced Abiathar as chief priest. Zadok himself traced his heritage back to one of Aaron's son, Eleazar. So he wasn't totally an outsider, but it was definitely a transition that would have been noticed.
Notice the strictness under which the priests were able to operate. They were not to drink wine while they were in the temple, which is different from today when the priests need to finish whatever wine is left over. They are only to marry a virgin, or a widow of a priest. They also received no land or investments apart from what the Lord provides to them. God wanted to be their only investment. All that the priests owned was wrapped up in who God was to them. I like that minimalism.