9 Something else I am admonished to say in this place of the loftiness of our Head Himself: for He was made weak even unto death, and He took on Him the weakness of flesh, in order that the chickens of Jerusalem He might gather under His wings, like a hen showing herself weak with her little ones. For have we not observed this thing in some bird at some time or other, even in those which build nests before our eyes, as the house-sparrows, as swallows, so to speak, our annual guests, as storks, as various sorts of birds, which before our eyes build nests, and hatch eggs, feed chickens, as the very doves which daily we see; and some bird to become weak with her chickens, have we not known, have we not looked upon, have we not seen? In what way does a hen experience this weakness? Surely a known fact I am speaking of, which in our sight is daily taking place. How her voice grows hoarse, how her whole body is made languid? The wings droop, the feathers are loosened, and you see around the chickens some sick thing, and this is maternal love which is found as weakness. Why was it therefore, but for this reason, that the Lord willed to be as a Hen, saying in the Holy Scripture, “Jerusalem, Jerusalem, how often have I willed to gather your sons, even as a hen her chickens under her wings, and you have not been willing.” But He has gathered all nations, like as a hen her chickens....
10. “And You, Lord God of virtues, God of Israel.” Thou God of Israel, that art thought to be but God of one nation, which worships You, when all nations worship idols, Thou God of Israel, “Give heed unto the visiting all nations.” Fulfilled be that prophecy wherein Isaiah in Your person speaks to Your Church, Your holy City, that barren one of whom many more are the sons of Her forsaken than of her that has a husband. To Her indeed has been said, “Rejoice, you barren, that bear not,” etc., more than of the Jewish nation which has a Husband, which has received the Law, more than of that nation which had a visible king. For your king is hidden, and more sons to you there are by a hidden Bridegroom....The Prophet adds, “Enlarge the place of Your tabernacle, and Your courts fix thou: there is no cause for you to spare, extend further your cords, and strong stakes set thou again and again on the right and on the left.” Upon the right keep good men, on the left keep evil men, until there come the fan: occupy nevertheless all nations; bidden to the marriage be good men and evil men, filled be the marriage with guests; it is the office of servants to bid, of the Lord to sever. “Cities which had been forsaken You shall inhabit:” forsaken of God, forsaken of Prophets, forsaken of Apostles, forsaken of the Gospel, full of demons. For You shall prevail; and blush not because abominable You have been. Therefore though there have risen up upon you strong men, blush not: when against the name of Christ laws were enacted, when ignominy and infamy it was to be a Christian. “Blush not because abominable You have been: for confusion for everlasting You shall forget, of the ignominy of Your widowhood You shall not be mindful.”...
11. “Have not pity upon all men that work iniquity.” Here evidently He is terrifying. Whom would He not terrify? What man falling back upon his own conscience would not tremble? Which even if to itself it is conscious of godliness, strange if it be not in some sort conscious of iniquity. For whosoever does sin, also does iniquity. “For if You shall have marked iniquities, O Lord, what man shall abide it?” And nevertheless a true saying it is, and not said to no purpose, and neither is nor will it be possible to be void, “Have not pity upon all men that work iniquity.” But He had pity even upon Paul, who at first as Saul wrought iniquity. For what good thing did he, whence he might deserve of God? Did he not hate His Saints unto death? did he not bear letters from the chief of the priests, to the end that wheresoever he might find Christians, to punishment he should hurry them? When bent upon this, when there proceeding, breathing and panting slaughter, as the Scripture testified of him, was he not from Heaven with a mighty voice summoned, thrown down, raised up; blinded, lightened; slain, made alive; destroyed, restored? In return for what merit? Let us say nothing; himself rather let us hear: “I that before have been,” he says, “a blasphemer, and persecutor; and injurious, but mercy I have obtained.” Surely “You would not have pity upon all men that work iniquity:” this in two ways may be understood: either that in fact not any sins does God leave unpunished; or that there is a sort of iniquity, on the workers whereof God has indeed no pity.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)