28 “Announcing His Word unto Jacob, His Righteousnesses and Judgments unto Israel”. What “Righteousnesses,” what “Judgments”? Because whatever mankind had suffered here before, when it was “snow” and “mist” and “crystal,” it suffered for the deserts of its pride and uplifting against God. Let us go back to the origin of our fall, and see that most truly is it sung in the Psalm, “Before I was troubled I went wrong.” But he who says, “Before I was troubled I went wrong,” says also, “It is good for me that You have humbled me, that I may learn Your Righteousnesses.” These righteousnesses Jacob learned from God, who made him to wrestle with an Angel; under the guise of which Angel, God Himself wrestled with him.
He held Him, he exerted violence to hold Him, he prevailed to hold Him: He caused Himself to be held, in mercy, not in weakness. Jacob therefore wrestled, and prevailed: he held Him and when he seemed to have conquered Him asked to be blessed of Him. How did he understand with Whom he had wrestled, Whom he had held? Wherefore did he wrestle violently, and hold Him? Because “the kingdom of heaven suffers violence, and the violent take it by force.” Wherefore then did he wrestle?
Because it is with toil. Wherefore do we with difficulty hold, what we so easily lose? Lest, easily getting back what we have lost, we learn to lose that which we hold. Let man have toil to hold: he will hold firmly, what he has only held after toil. These His judgments therefore God manifested to Jacob and Israel....
Source: The Enarrations, or Expositions, on the Psalms (New Advent)