10 Whence the Psalmist at once adds: “As for such as turn aside, the Lord shall lead them forth unto strangling with the workers of unrighteousness”: that is, those whose deeds they have imitated; because they took delight in their present pleasures, and did not believe in their punishments to come. What then shall they have, who are righteous in heart, and who turn not back? Let us now come to the heritage itself, brethren, for we are sons. What shall we possess? What is our heritage?
What is our country: what is it called? Peace. In this we salute you, this we announce to you, this the mountains receive, and the little hills receive as righteousness. Peace is Christ: “for He is our peace, who has made both one, and has broken down the middle wall of partition between us.” Since we are sons, we shall have an inheritance. And what shall this inheritance be called, but peace? And consider that they who love not peace are disinherited. Now they who divide unity, love not peace.
Peace is the possession of the pious, the possession of heirs. And who are heirs? Sons....Since then Christ the Son of God is peace, He therefore came to gather together His own, and to separate them from the wicked. From what wicked men? From those who hate Jerusalem, who hate peace, who wish to tear unity asunder, who believe not peace, who preach a false peace to the people, and have it not. To whom answer is made, when they say, “Peace be with you,” “And with your spirit:” but they speak falsely, and they hear falsely.
Unto whom do they say, Peace be with you? To those whom they separate from the peace of the whole earth. And unto whom is it said, “And with your spirit”? To those who embrace dissensions, and who hate peace. For if peace were in their spirit, would they not love unity, and leave dissensions? Speaking then false words, they hear false words. Let us speak true words, and hear true words. Let us be Israel, and let us embrace peace; for Jerusalem is a vision of peace, and we are Israel, “and peace is upon Israel.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)