4 But who is “the righteous” man, who “has never been seen forsaken, nor his seed begging bread”? If you understand what is meant by “bread,” you understand who is meant by him. For the “bread” is the Word of God, which never departs from the righteous man's mouth....See now if “holy meditation does 'keep you'” in the rumination of this bread, then “have you never seen the righteous forsaken, nor his seed begging bread.”
5. “He is always merciful, and lends”. “Fœneratur” is used in Latin indeed, both for him who lends, and for him who borrows. But in this passage the meaning is more plain, if we express it by “fœnerat.” What matters it to us, what the grammarians please to rule? It were better for us to be guilty of a barbarism, so that you understand, than that in our propriety of speech ye be left unprovided. Therefore, that “righteous man is all day merciful, and (fœnerat) lends.” Let not the lenders of money on usury, however, rejoice. For we find it is a particular kind of lender that is spoken of, as it was a particular kind of bread; that we may, in all passages, “remove the roof,” and find our way to Christ. I would not have you be lenders of money on usury; and I would not have you be such for this reason, because God would not have you....Whence does it appear that God would not have it so? It is said in another place, “He that puts not out his money to usury.” And how detestable, odious, and execrable a thing it is, I believe that even usurers themselves know. Again, on the other hand, I myself, nay rather our God Himself bids you be an usurer, and says to you, “Lend unto God.” If you lend to man, have you hope? And shall you not have hope, if you lend to God? If you have lent your money on usury to man, that is, if you have given the loan of your money to one, from whom you expect to receive something more than you have given, not in money only, but anything, whether it be wheat, or wine, or oil, or whatever else you please, if you expect to receive more than you have given, you are an usurer, and in this particular are not deserving of praise, but of censure. “What then,” you say, “am I to do, that I may 'lend' profitably?” Consider what the usurer does. He undoubtedly desires to give a less sum, and to receive a larger; do thou this also; give thou a little, receive much. See how your principal grows, and increases! Give “things temporal,” receive “things eternal:” give earth, receive heaven! And perhaps you would say, “To whom shall I give them?” The self-same Lord, who bade you not lend on usury, comes forward as the Person to whom you should lend on usury! Hear from Scripture in what way you may “lend unto the Lord.” “He that has pity on the poor, lends unto the Lord.” For the Lord wants not anything of you. But you have one who needs somewhat of you: you extend it to him; he receives it. For the poor has nothing to return to you, and yet he would himself fain requite you, and finds nothing wherewith to do it: all that remains in his power is the good-will that desires to pray for you. Now when the poor man prays for you, he, as it were, says unto God, “Lord, I have borrowed this; be Thou surety for me.” Then, though you have no bond on the poor man to compel his repayment, yet you have on a sponsible security. See, God from His own Scriptures says unto you; “Give it, and fear not; I repay it. It is to Me you give it.” In what way do those who make themselves sureties for others, express themselves? What is it that they say? “I repay it: I take it upon myself. It is to me you are giving it.” Do we then suppose that God also says this, “I take it on Myself. It is unto me you give it”? Assuredly, if Christ be God, of which there is no doubt, He has Himself said, “I was an hungred, and you gave Me meat.” And when they said unto Him, “When saw we You hungry?” that He might show Himself to be the Surety for the poor, that He answers for all His members, that He is the Head, they the members, and that when the members receive, the Head receives also; He says, “Inasmuch as you have done it to one of the least of these that belong to Me, you have done it unto Me.” Come, thou covetous usurer, consider what you have given; consider what you are to receive. Had you given a small sum of money, and he to whom you had given it were to give you for that small sum a great villa, worth incomparably more money than you had given, how great thanks would you render, with how great joy would you be transported! Hear what possession He to whom you have been lending bestows. “Come, you blessed of My Father, receive” — What? The same that they have given? God forbid! What you gave were earthly things, which, if you had not given them, would have become corrupted on earth. For what could you have made of them, if you had not given them? That which on earth would have been lost, has been preserved in heaven. Therefore what we are to receive is that which has been preserved. It is your desert that has been preserved, your desert has been made your treasure. For consider what it is that you are to receive. Receive— “the kingdom prepared for you from the foundation of the world.” On the other hand, what shall be their sentence, who would not “lend”? “Go ye into everlasting fire, prepared for the devil and his angels.” And what is the kingdom which we receive called? Consider what follows: “And these shall go into everlasting burning; but the righteous into life eternal.” Make interest for this; purchase this. Give your money on usury to earn this. You have Christ throned in heaven, begging on earth. We have discovered in what way the righteous lends. “He is always merciful, and lends.”
6. “And his seed is blessed.” Here too let not any carnal notion suggest itself. We see many of the sons of the righteous dying of hunger; in what sense then will his seed be blessed? His seed is that which remains of him afterwards; that wherewith he sows here, and will hereafter reap. For the Apostle says, “Let us not be weary in well-doing; for in due season we shall reap if we faint not. As we have therefore time,” he says, “let us do good unto all men.” This is that “seed” of yours which shall “be blessed.” You commit it to the earth, and gather ever so much more; and do you lose it in committing it to Christ? See it expressly termed “seed” by the Apostle, when he was speaking of alms. For this he says; “He which sows sparingly, shall reap also sparingly; and he which sows in blessings, shall also reap in blessings.”...
Source: The Enarrations, or Expositions, on the Psalms (New Advent)