Gregory the Great, on Ezek 40:46

“But the chamber that looketh towards the north shall be for the priests that watch over the ministry of the altar. These are the sons of Sadoc, who among the sons of Levi, come near to the Lord, to minister to him.”

“But concerning both orders of priests it is added: These are the sons of Zadok, who approach from the sons of Levi to the Lord to minister to Him. Zadok in Latin means just. But who is just, except Him to whom it is said: You are just, Lord, and Your judgment is right? And who are the sons of the just, except those of whom it is written: But as many as believed in Him, He gave them power to become sons of God? Now Levi is interpreted as taken up. But who has been taken up by the Lord, except the faithful people, who through the sacraments of faith have been separated from the faithless? Therefore all who perseveringly devote themselves to spiritual activities are sons of the just. And from the sons of the people taken up they approach the Lord to minister to Him, because from those same faithful ones are chosen those who come to the ministry of almighty God and devote themselves to heavenly studies for the instruction of the people.”

Imported from an open dataset — not yet checked against the printed edition.