2Sam 8:2

“In the second book of Kings [Samuel], where David defeated the Moabites, Scripture records the measuring out of two separate lines for life and two for death. The significance of setting aside some Moabites for life and others for death is made clear by the story of Orpah and Ruth. Orpah, who turned back to idolatry and her ancient country, was destined for death; Ruth, following her mother-in-law, whose name means "pleasant," says, "Your people shall be my people, and your God my God."”

“"And he struck down Moab, and measured them with a line, aligning them to the ground, etc." [2 Samuel 8:2] What is written about David: "And he smote Moab, and measured them with a line, laying them on the ground," should be understood hyperbolically. For it was not possible that men living on the earth would be so humbled that, lying on the ground, they would appear equal with the ground itself, as confirmed by a line stretched over them; but the Scripture wanted to accumulate the immense humiliation of the captured and oppressed nation with this word, to say they were made equal to the ground, as if by God they were emasculated and despised, so that they living on earth no longer mattered more than the ground that had no people. You have many examples of this kind of expression in the Scriptures, such as that one from the Gospel: "And there are also many other things which Jesus did; if they were written every one, I suppose that even the world itself could not contain the books that should be written" (John XXI). For how could the world not contain the books that could have been written in the world? But to imply the greatness and multitude of the Lord's deeds, the Scripture wished to use such an expression. And in David's lament, "They were swifter than eagles, stronger than lions" (II Samuel I). Which is similar to that secular expression: "Who would surpass the whiteness of snow, in their courses the winds." That he said "measured them with a line," he put the line allegorically for destiny, because fields are usually measured by a line. Hence it is written: "And he divided the land to them by lot with a measuring line." It means that David would distribute the regions of the Moabites to the heirs according to his will, as freely as any possessor might divide his own fields at his whim by stretching the line here and there. He measured two lines, one for putting to death, and one for keeping alive. And this is said allegorically, signifying that David had the power, with no one contradicting, to put to death those who were rebellious and to spare those who were submissive.”