Psalm 23 is from David. Many people know that.

But I am wondering how many people know what he did with the Moabites?

“David also defeated the Moabites. He made them lie down on the ground and measured them off with a length of cord. Every two lengths of them were put to death, and the third length was allowed to live. So the Moabites became subject to David and brought him tribute.”

Second Samuel 8:2-3