Benefits should be conferred on the poor rather than on the rich, for these latter either think a return is expected from them, or else they are angry at seeming to be indebted for such an action. But the poor man makes God the debtor in his place, and freely owns to the benefits he has received. To these remarks is added a warning to despise riches.
126. But what advantage is it to you to show favour to a rich man? Is it that he is more ready to repay one who loves him? For we generally show favour to those from whom we expect to receive a return of favour. But we ought to think far more of the weak and helpless, because we hope to receive, on behalf of him who has it not, a recompense from the Lord Jesus, Who in the likeness of a marriage feast has given us a general representation of virtue. By this He bids us confer benefits rather on those who cannot give them to us in return, teaching us to bid to our feasts and meals, not those who are rich, but those that are poor. For the rich seem to be asked that they may prepare a banquet for us in return; the poor, as they have nothing wherewith to make return, when they receive anything, make the Lord to be our recompense Who has offered Himself as surety for the poor.
127. In the ordinary course of things, too, the conferring of a benefit on the poor is of more use than when it is conferred on the rich. The rich man scorns the benefit and is ashamed to feel indebted for a favour. Nay, moreover, whatever is offered to him he takes as due to his merits, as though only a just debt were paid him; or else he thinks it was but given because the giver expected a still greater return to be made him by the rich man. So, in accepting a kindness, the rich man, on that very ground, thinks that he has given more than he ever received. The poor man, however, though he has no money wherewith he can repay, at least shows his gratitude. And herein it is certain that he returns more than he received. For money is paid in coins, but gratitude never fails; money grows less by payment, but gratitude fails when held back, and is preserved when given to others. Next— a thing the rich man avoids— the poor man owns that he feels bound by the debt. He really thinks help has been given him, not that it has been offered in return for his honour. He considers that his children have been again given him, that his life is restored and his family preserved. How much better, then, is it to confer benefits upon the good than on the ungrateful.
128. Wherefore the Lord said to His disciples: “Take neither gold nor silver nor money.” Whereby as with a sickle He cuts off the love of money that is ever growing up in human hearts. Peter also said to the lame man, who was always carried even from his mother's womb: “Silver and gold have I none, but what I have give I you. In the Name of Jesus Christ of Nazareth, arise and walk.” So he gave not money, but he gave health. How much better it is to have health without money, than money without health! The lame man rose; he had not hoped for that: he received no money; though he had hoped for that. But riches are hardly to be found among the saints of the Lord, so as to become objects of contempt to them.
Source: On the Duties of the Clergy (New Advent)