9 “He shall not give to God his propitiation, and the price of the redemption of his soul”. He trusts in his virtue, and in the abundance of his riches does glory, who “shall not give to God his propitiation:” that is, satisfaction whereby he may prevail with God for his sins: “nor the price of the redemption of his soul,” who relies on his virtue, and on his friends, and on his riches. But who are they that give the price of the redemption of their souls? They to whom the Lord says, “Make to yourselves friends of the Mammon of unrighteousness, that they may receive you into everlasting habitations.” They give the price of the redemption of their soul who cease not to do almsdeeds.
So those whom the Apostle charges by Timothy he would not have to be proud, lest they should glory in the abundance of their riches. Lastly, what they possessed he would not have to grow old in their hands: but that something should be made of it to be for the price of the redemption of their souls. For he says, “Charge them that are rich in this world, that they be not high-minded: nor trust in uncertain riches, but in the living God, who gives us richly all things to enjoy.” And as if they had said, “What shall we then make of our riches?” he continues, “Let them be rich in good works, ready to distribute, willing to communicate,” and they will not lose that.
How know we? Hear what follows. “Let them lay up for themselves a good foundation against the time to come, that they may lay hold on the true life.” So shall they give the price of the redemption of their soul. And our Lord counsels this: “Make for yourselves bags which wax not old, a treasure in the heavens that fails not, where thief approaches not, neither moth corrupts.” God would not have you lose your wealth, but He has given you counsel to change the place thereof. Let your love understand.
Suppose your friend were just now to enter your house, and find you had placed your store of grain in a damp place, and he knew the natural proneness of grain to decay, which thou perchance knew not, he would give you counsel of this sort, saying, “Brother, you are losing what with great toil you have gathered, you have placed it in a damp place, in a few days this grain will decay.” And what am I to do, brother? “Raise it into a higher place.” You would hearken to your friend suggesting that you should raise grain from a lower to a higher chamber, and do you not hearken to Christ charging you to lift your treasure from earth to heaven, where not what you keep in store may be paid to you, but that you may keep in store earth, may receive heaven, may keep in store things mortal, may receive things everlasting, that while you lend Christ to receive at your hands but a small loan upon earth, He may repay you a great recompense in Heaven?
Nevertheless, they whom “the iniquity of their heel shall compass,” because they trust in their virtue, and in the abundance of their riches do glory, and rely on human friends who are able to help them in nothing, “shall not give to God their propitiation, and the price of the redemption of their souls.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)