"The poor are destitute of all worldly riches because, even though they be surrounded by wealth, they realize how unreliable it is. They cry to God, for they have nothing in this world to delight or hold them but are subject to many tribulations and temptations. They are in the presses, as it were, and emit streams of wine and oil. What is this wine, this oil, but good desires? For their desire for God remains. They no longer love the world: they love him who made heaven and earth. They love him, but are not yet with him. The satisfaction of their desire is delayed so that the desire may intensify; it intensifies so that it may be capable of receiving God. For it is no small thing that God intends for those who desire, and no little training is required if we are to be able to receive so great a good. God's gift will not be something he has made, but himself, who made all things. Train yourselves, then, to embrace God; long practiced be your desire for what you will possess without end."
Augustine of Hippo (AD 354-430), Expositions of the Psalms 147, 3: CCL 40, 2140-2141