6 But it is a great thing to have the heart established, and not to be moved, while they rejoice who love what they see, and mock at him who hopes for what he sees not; “what the Lord has prepared for them that love Him.” How great is the value of this which is not seen, and it is bought for so much as each man is able to give for it. On this account he also “dispersed abroad, and gave to the poor”: he saw not, yet he kept buying; but He was storing up the treasure in heaven, who deigned to hunger and thirst in the poor on earth. It is no wonder then if “his righteousness remains for ever:” He who created the ages being his guardian. “His horn,” whose humility was scorned by the proud, “shall be exalted with honour.”
7. “The ungodly shall see it, and he shall be angered”: this is that late and fruitless repentance. For with whom rather than himself is he “angered,” when he shall say, “Our pride, what has it profited us? The boastfulness of our riches, what has it given us?” seeing the horn of him exalted with honour, who “dispersed abroad, and gave to the poor.” “He shall gnash with his teeth, and consume away:” for “there shall be weeping and gnashing of teeth.” For he will no more bring forth leaves and bloom, as would happen if he had repented in season: but he will then repent, when “the desire of the ungodly shall perish,” no consolation succeeding. “The desire of the ungodly shall perish,” when “all things shall pass away like a shadow,” when the flower shall fall down on the withering of the grass. “But the word of the Lord that endures for ever,” as it is mocked by the vanity of the falsely happy, so will laugh at the perdition of the same when truly miserable.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)