7 Men hear that common proverb; and the proverbs of God slumber in them. What proverb? “Better in hand than in hope.” Unhappy man, what have you in hand? You say, “Better in hand.” Hold it so as not to lose it, and then say, “Better in hand.” But if you hold it not, why do you not hold fast that which you can not lose? What then have you in hand? Gold. Keep it in hand, therefore: if you have it in hand, let it not be taken away without your consent. But if through gold also you are carried where you wish not, and if a more powerful robber seeks you, because he finds you a less powerful robber; if a stronger eagle pursue you, because you have carried off a hare before him: the lesser was your prey, you will be a prey unto the greater. Men see not these things in human affairs: by so much avarice are they blinded...
Source: The Enarrations, or Expositions, on the Psalms (New Advent)