10 Lastly, there follows, “For they have eaten up Jacob, and his place they have made desolate”....How we should view “the place” of Jacob, must be understood. For rather the place of Jacob may be supposed to be that city, wherein was also the Temple, whither-unto the whole of that nation for the purpose of sacrifice and worship, and to celebrate the Passover, the Lord had commanded to assemble. For if the assemblies of Christians, letted and suppressed by persecutors, has been what the Prophet would have to be understood, it would seem that he should have said, places made desolate, not place. Still we may take the singular number as put for the plural number; as dress for clothes, soldiery for soldiers, cattle for beasts: for many words are usually spoken in this manner, and not only in the mouths of vulgar speakers, but even in the eloquence of the most approved authorities. Nor to divine Scripture herself is this form of speech foreign. For even she has put frog for frogs, locust for locusts, and countless expressions of the like kind. But that which has been said, “They have eaten up Jacob,” the same is well understood, in that many men into their own evil-minded body, that is, into their own society, they have constrained to pass.
11....He subjoins, “Remember not our iniquities of old”. He says not bygone, which might have even been recent; but “of old,” that is, coming from parents. For to such iniquities judgment, not correction, is owing. “Speedily let Your mercies anticipate us.” Anticipate, that is, at Your judgment. For “mercy exalts above in judgment.” Now there is “judgment without mercy,” but to him that has not showed mercy. But whereas he adds, “for we have become exceeding poor:” unto this end he wills that the mercies of God should be understood to anticipate us; that our own poverty, that is, weakness, by Him having mercy, should be aided to do His commandments, that we may not come to His judgment to be condemned.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)