Ezekiel 40:45

"And he said to me: This is the treasury that faces the southern way of the priests, who keep watch in the temple's guardrooms. Furthermore, the treasury that faces the way of the north will be for the priests who serve at the altar: these are the sons of Zadok who come near from the sons of Levi to the Lord, to minister to Him." Finally, that man whose pen and cord were in his hand, having led the prophet into the inner courtyard which overlooked the southern road, spoke these words: 'This is the treasury or council chamber; and as Theodotius set it up, the chamber, which is separated for the dwelling of the priests, is for the observation of the temple guards. Furthermore, the treasury which overlooks the northern road will belong to the priests who stand guard at the service of the altar.' In which it should be noted that the priests to whom the custody of the temple has been entrusted dwell in the treasury, which faces the south, where the fullest light is. But those who stand guard at the ministry of the altar, where victims are offered for sin, should be in the treasury facing the north, for those who come from the north and offer victims for sins, desiring to receive and save them. Both of these, serving the Lord in their respective duties, are called the sons of Zadok, which means righteous or justifying. For God, the Almighty, whose name is written: The Lord is righteous and loves justice; His face has seen equity (Psalm 11: 8). But these are the sons of Sadoc of the sons of Levi, which is interpreted as 'assumed'. And they themselves are assumed by the Lord, so that they may approach Him, and never is it said of Moses alone: Moses approached the Lord; but also all who serve and minister to Him are said to draw near to the Lord.

In these words of the prophet we must first inquire who are the priests of the greater order, whether those who keep watch in the guardianships of the temple, or those who serve at the ministry of the altar. But because shortly afterward it is added: "The altar was before the face of the temple," it is clearly shown that those are priests of the greater order who keep watch in the guardianships of the temple, because indeed they minister at the altar which is within. But those who keep watch at the altar which is before the face of the temple are inferior by as much as they minister in the outer areas. Therefore we must inquire who the priests are who guard the temple, and who are said to keep watch for the ministry of the altar. The teacher of the Gentiles, writing to the faithful, says: "The temple of God is holy, which you are." Who then are the priests who guard the temple of God, if not those who by praying, by preaching, by keeping watch in spiritual activities, defend the holy Church from the assaults of malignant spirits, from the persuasions of the wicked, from the errors of heretics? Was he not a guardian of the temple who, enumerating the labors of his suffering, says: "In labor and hardship, in many watchings, in hunger and thirst, in many fastings, in cold and nakedness"? And immediately he adds: "Besides those things which are from without, my daily urgency, the care of all the churches." Consider, I ask, with how great solicitude the guardian of the temple keeps watch. For behold, he suffers inestimable things in himself, and he shares the solicitude of his heart with others. Of what virtue, I ask, is it to think more about the welfare of one's neighbors than about one's own affliction? Who can worthily estimate this? Who can worthily weigh it? He labors, he grieves, he hungers, he thirsts, he is cold, he fasts, he keeps watch, and yet while keeping watch he thinks about the care of all the churches. Behold, a most diligent guardian of the temple is set forth as an example. Let whoever is able imitate him. For to suffer adversities for the truth, to bestow good things upon neighbors, to keep watch concerning the care of souls, to seek out and restrain anyone from falling into faithlessness, into pride, into plundering, or into impurity—this is to guard the temple of God, that is, the holy Church.