10 He at once adds, as unto the seats themselves, “Enquire ye the things that are for the peace of Jerusalem”. O you seats, who now sit unto judgment, and are made the seats of the Lord who judges (since they who judge, enquire; they who are judged, are enquired of), “Enquire ye,” he says, “the things that are for the peace of Jerusalem.” What will they find by asking? That some have done deeds of charity, that others have not. Those whom they shall find to have done deeds of charity, they will summon them unto Jerusalem; for these deeds are “for the peace of Jerusalem.” Love is a powerful thing, my brethren, love is a powerful thing. Do ye wish to see how powerful a thing love is?...If charity be destitute of means, so that it cannot find what to bestow upon the poor, let it love: let it give “one cup of cold water;” as much shall be laid to its account, as to Zaccheus who gave half his patrimony to the poor. Wherefore this? The one gave so little, the other so much, and shall so much be imputed to the former? Just so much. For though his resources are unequal, his charity is not unequal.
11....“And plenteousness,” he adds, “for them that love you.” He addresses Jerusalem herself, They have plenteousness who love her. Plenteousness after want: here they are destitute, there they are affluent; here they are weak, there they are strong; here they want, there they are rich. How have they become rich? Because they gave here what they received from God for a season, and received there what God will afterwards pay back for evermore. Here, my brethren, even rich men are poor. It is a good thing for a rich man to acknowledge himself poor: for if he think himself full, that is mere puffing, not plenteousness. Let him own himself empty, that he may be filled. What has he? Gold. What has he not yet? Everlasting life. Let him consider what he has, and see what he has not. Brethren, of that which he has, let him give, that he may receive what he has not; let him purchase out of that which he has, that which he has not, “and plenteousness for them that love you.”
12. “Peace be in your strength”. O Jerusalem, O city, who art being built as a city, whose partaking is in “The Same:” “Peace be in your strength:” peace be in your love; for your strength is your love. Hear the Song of songs: “Love is strong as death.” A great saying that, brethren, “Love is strong as death.” The strength of charity could not be expressed in grander terms than these, “Love is strong as death.” For who resists death, my brethren? Consider, my brethren. Fire, waves, the sword, are resisted: we resist principalities, we resist kings; death comes alone, who resists it? There is nought more powerful than it. Charity therefore is compared with its strength, in the words, “Love is strong as death.” And since this love slays what we have been, that we may be what we were not; love creates a sort of death in us. This death he had died who said, “The world is crucified unto me, and I unto the world:” this death they had died unto whom he said, “You are dead, and your life is hid with Christ in God.” Love is strong as death...
Source: The Enarrations, or Expositions, on the Psalms (New Advent)