Charles H. Spurgeon on Psalms 52:1

Why boasteth thyself in mischief, O mighty man? Doeg had small matter for boasting in having procured the slaughter of a band of defenceless priests. A mighty man indeed to kill men who never touched a sword! He ought to have been ashamed of his cowardice. He had no room for exultation! Honourable titles are but irony where the wearer is mean and cruel. If David alluded to Saul, he meant by these words pityingly to say, "How can one by nature fitted for nobler deeds, descend to so low a level as to find a theme for boasting in a slaughter so heartless and mischievous?" The goodness of God endureth continually. A beautiful contrast. The tyrant's fury cannot dry up the perennial stream of divine mercy. If priests be slain their Master lives. If Doeg for awhile triumphs the Lord will outlive him, and right the wrongs which he has done. This ought to modify the proud exultations of the wicked, for after all, while the Lord liveth, iniquity has little cause to exalt itself.