The vengeance, i.e. the vengeance of God upon his implacable enemies; not simply for himself, but for the blessed effects of it, the vindication of God's honour, and the deliverance of himself and of all good men. He shall wash his feet in the blood of the wicked, i.e. there shall be so great a slaughter of his enemies, that he might, if he so pleased, wash his feet in their blood. See the same or like expressions, Psalms 68:23 Isaiah 63:3 Revelation 14:20.
Related Commentaries of Psalms 58:10
Psalms 58:10
10 The righteous shall rejoice when he seeth the vengeance: he shall wash his feet in the blood of the wicked.