The righteous will rejoice when he sees the vengeance;
he will bathe his feet in the blood of the wicked.
Mankind will say, “Surely there is a reward for the righteous;
surely there is a God who judges on earth.” —Psalm 58:10-11
Imprecatory psalms are difficult to understand. Here are two comments that help us:
He will have no hand in meting out, neither will he rejoice in the spirit of revenge, but his righteous soul shall acquiesce in the judgments of God, and he shall rejoice to see justice triumphant.
When God’s holy indignation is thus conspicuously displayed, the godly should thankfully recognize God’s just displeasure. Pity for the miserable offenders they should feel, but joy in God’s glory should prevail. The blood of the wicked should be as a fountain, in which their feet should wash, and as a warning to walk more warily.