8:1-8. David subdued the Philistines. They had long been troublesome to Israel. And after the long and frequent struggles the saints have with the powers of darkness, like Israel with the Philistines, the Son of David shall tread them all under foot, and make the saints more than conquerors. He smote the Moabites, and made them tributaries to Israel. Two parts he destroyed, the third part he spared. The line that was to keep alive, though it was but one, is ordered to be a full line. Let the line of mercy be stretched to the utmost. He smote the Syrians. In all these wars David was protected, for this in his psalms he often gives glory to God.

2. he smote Moab, and measured them with a line—This refers to a well-known practice of Eastern kings, to command their prisoners of war, particularly those who, notorious for the atrocity of their crimes or distinguished by the indomitable spirit of their resistance, had greatly incensed the victors, to lie down on the ground. Then a certain portion of them, which was determined by lot, but most commonly by a measuring-line, were put to death. Our version makes him put two-thirds to death, and spare one-third. The Septuagint and Vulgate make one-half. This war usage was not, perhaps, usually practised by the people of God; but Jewish writers assert that the cause of this particular severity against this people was their having massacred David's parents and family, whom he had, during his exile, committed to the king of Moab.