4 Wisdom therefore must be thirsted after, righteousness must be thirsted after. With it we shall not be satisfied, with it we shall not be filled, save when this life shall have been ended, and we shall have come to that which God has promised. For God has promised equality with Angels: and now the Angels thirst not as we do, they hunger not as we do; but they have the fullness of truth, of light, of immortal wisdom. Therefore blessed they are, and out of so great blessedness, because they are in that City, the Heavenly Jerusalem, afar from whence we now are sojourning in a strange land, they observe us sojourners, and they pity us, and by the command of the Lord they help us, in order that to this common country sometime we may return, and there with them sometime with the Lord's fountain of truth and eternity we may be filled.
Now therefore let our soul thirst: whence does our flesh also thirst, and this in many ways? “In many ways for You,” he says, “my flesh also.” Because to our flesh also is promised Resurrection. As to our soul is promised blessedness, so also to our flesh is promised resurrection....For if God has made us that were not, is it a great thing for Him to make again us that were? Therefore let not this seem to you to be incredible, because ye see dead men as it were decaying, and passing into ashes and into dust.
Or if any dead man be burned, or if dogs tear him in pieces, do ye think that from this he will not rise again? All things which are dismembered, and into a sort of dust do decay, are entire with God. For into those elements of the world they pass, whence at first they have come, when we were made: we do not see them; but yet God will bring them forth, He knows whence, because even before we were, He created us from whence He knew. Such a resurrection of the flesh therefore to us is promised, as that, although it be the same flesh that now we carry which is to rise again, yet it has not the corruption which now it has.
For now because of the corruption of frailty, if we eat not, we faint and are hungry; if we drink not, we faint and are thirsty; if long time we watch, we faint and sleep; if long time we sleep, we faint, therefore we watch....Secondly, see how without any standing is our flesh: for infancy passes away into boyhood, and you seek infancy, and infancy is not, for now instead of infancy is boyhood: again this same also passes into youth, you seek boyhood and findest not: the young man becomes a middle-aged man, you seek the young man and he is not: the middle-aged man becomes an old man, you seek a middle-aged man and findest not: and an old man dies, you seek an old man and findest not: our age therefore stands not still: everywhere is weariness, everywhere faintness, everywhere corruption.
Observing what a hope of resurrection God promises to us, in all those our manifold faintings we thirst for that incorruption: and so our flesh manifoldly does thirst for God.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)