1 Behold, one poor man prays, and prays not in silence. We may therefore hear him, and see who he is: whether it be not perchance He, of whom the Apostle says, “Though He was rich, yet for your sakes He became poor, that you through His poverty might be rich.” If it is He, then, how is He poor? For in what sense He is rich, who sees not? What then is richer than He, by whom riches were made, even those which are not true riches? For through Him we have even these riches, ability, memory, character, health of body, the senses, and the conformation of our limbs: for when these are safe, even the poor are rich.
Through Him also are those greater riches, faith, piety, justice, charity, chastity, good conduct: for no man has these, except through Him who justifies the ungodly....Behold, how rich! In one so rich, how are we to recognise these words? “I have eaten ashes as it were bread: and mingled my drink with weeping.” Have these so great riches come to this? The former state is a very high one, this is a very lowly one....Yet still examine whether this poor man be He; since, “The Word was made flesh, and dwelt among us.” Reflect also upon these words: “I am Your servant, and the Son of Your handmaid.” Observe, this handmaid, chaste, a virgin, and a mother: for there He received our poverty, when He was clothed in the form of a servant, emptying Himself; lest you should dread His riches, and in your beggarly state should not dare approach Him.
There, I say, He put on the form of a servant, there He was clothed with our poverty; there He made Himself poor, and us rich. We are now drawing near to understand these things of Him: nevertheless we may not as yet rashly pronounce....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)