Albert Barnes Commentary Psalms 59:11

"Slay them not, lest my people forget: Scatter them by thy power, and bring them down, O Lord our shield." — Psalms 59:11 (ASV)

Slay them not, lest my people forget—The meaning of this seems to be: Do not destroy them at once, so that, being removed from the way, the people do not forget what was done, or lose the impression that it is desirable to produce by their punishment. Let them live, and let them wander about as exiles under the divine displeasure, so that they may be permanent and enduring proofs of the justice of God, of the evil of sin, and of the danger of violating the divine law.

So Cain wandered on the earth (Genesis 4:12–14), a living proof of that justice which avenges murder; and so the Jews still wander, a lasting illustration of the justice which followed their rejection of the Messiah. The prayer of the psalmist, therefore, is that the fullest expression should be given to the divine sense of the wrong which his enemies had done, so that the salutary lesson should not be soon forgotten, but should be permanent and enduring.

Scatter them by your power—Break up their combinations, and let them go abroad as separate wanderers, proclaiming everywhere, by being thus vagabonds on the earth, the justice of God.

And bring them down—Humble them. Show them their weakness. Show them that they do not have power to contend against God.

O Lord our shield—See Psalms 5:12, note; Psalms 33:20, note. The words “our” here, and “my” in the former part of the verse, are designed to show that the author of the psalm regarded God as “his” God, and the people of the land as “his,” in the sense that he was identified with them, and felt that his cause was really that of the people.