Charles H. Spurgeon on Psalms 110:5

Shall strike through kings. To strike through notes a complete victory and full confusion of the enemy, all incurable wound, that they may stagger, and fall, and rise up no more, and that affliction may not arise a second time, Na 1:9; 1Sa 26:8. The only difficulty is what is meant by "kings". For which we must note that the kingdom of Christ is spiritual, and his war spiritual, and therefore his enemies for the most part spiritual. Edward Reynolds.