7 What then does it mean that the man was in infirmity thirty-eight years? I know, brethren, that I have spoken of this already; but even those who read forget, how much more they who hear but seldom? Attend therefore for a little while, Beloved. In the number forty, the accomplishment of righteousness is figured. The accomplishment of righteousness, in that we live here in labour, in toil, in self-restraint, in fastings, in watchings, in tribulations; this is the exercise of righteousness, to bear this present time, and to fast as it were from this world; not from the food of the body, which we do but seldom; but from the love of the world, which we ought to do always.
He then fulfils the law who abstains from this world. For he cannot love that which is eternal, unless he shall cease to love that which is temporal. Consider a man's love: think of it as, so to say, the hand of the soul. If it is holding anything, it cannot hold anything else. But that it may be able to hold what is given to it, it must leave go what it holds already. This I say, see how expressly I say it; “Whoso loves the world cannot love God; he has his hand engaged.” God says to him, “Hold what I give.”
He will not leave go what he was holding; he cannot receive what is offered. Have I said a man should not possess ought? If he is able, if perfection require this of him, let him not possess. If hindered by any necessity he is not able, let him possess, not be possessed; let him hold, not be held; let him be the lord of his possessions, not the slave; as says the Apostle “However, brethren, the time is short; it remains that both they that have wives, be as though they had not; and they who buy, as though they possessed not; and they who rejoice, as though they rejoiced not; and they who weep, as though they wept not; and they who use this world, as though they used it not; for the fashion of this world passes away.
I would have you be without carefulness.” What is, “Do not love what you possess in this world”? Let it not hold your hand fast, by which God must be held. Let not your love be engaged, whereby you can make your way to God, and cleave to Him who created you.
Source: Sermons on Selected Lessons of the New Testament (New Advent)