2 Samuel 8:1-2

1After this it came to pass that David attacked the Philistines and subdued them. And David took Metheg Ammah from the hand of the Philistines.

2Then he defeated Moab. Forcing them down to the ground, he measured them off with a line. With two lines he measured off those to be put to death, and with one full line those to be kept alive. So the Moabites became David’s servants, and brought tribute.