16 “You have loved righteousness, and hated iniquity”. See there “the rod of direction” described. “You have loved righteousness, and hated iniquity.” Draw near to that “rod;” let Christ be your King: let Him “rule” you with that rod, not crush you with it. For that rod is “a rod of iron;” an inflexible rod. “You shall rule them with a rod of iron: and break them in pieces like a potter's vessel.” Some He rules; others He “breaks in pieces:” He “rules” them that are spiritual: He “breaks in pieces” them that are carnal....Would He so loudly declare that He was about to smite you, if He wished to smite you?
He is then holding back His hand from the punishment of your offenses; but do not thou hold back. Turn you yourself to the punishment of your offenses: for unpunished offenses cannot be: punishment therefore must be executed either by yourself, or by Him: do thou then plead guilty, that He may reprieve you. Consider an instance in that penitential Psalm: “Hide Your face from my sins.” Did he mean “from me”? No: for in another passage he says plainly, “Hide not Your face from me.”
“Turn” then “Your face from my sins.” I would have You not see my sins. For God's “seeing” is animadverting upon. Hence too a Judge is said to “animadvert” on that which he punishes; i.e. to turn his mind on it, to bend it thereon, even to the punishment of it, inasmuch as he is the Judge. So too is God a Judge. “Turn Thou Your face from my sins.” But you yourself, if you would have God turn “His face” from them, turn not your own face from them. Observe how he proposes this to God in that very Psalm: “I acknowledge,” he says, “my transgression, and my sin is ever before me.” He would fain have that which he wishes to be ever before his own eyes, not be before God's eyes.
Let no one flatter himself with fond hopes of God's mercy. His sceptre is “a sceptre of righteousness.” Do we say that God is not merciful? What can exceed His mercy, who shows such forbearance to sinners; who takes no account of the past in all that turn unto Him? So love thou Him for His mercy, as still to wish that He should be truthful. For mercy cannot strip Him of His attribute of justice: nor justice of that of mercy. Meanwhile during the time that He postpones your punishment, do not thou postpone it.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)