Joab had treacherously murdered Abner and Amasa under David’s kingship. What Joab had done was an outstanding debt. Solomon transfers this guilt from his father David and from himself to Joab and Joab’s descendants. He means: “If Joab’s death does not entirely take away the guilt, I will put it on his children.” God does not tolerate guilt; it needs to be removed.
31 Le roi dit à Benaja: Fais comme il a dit, frappe-le, et enterre-le; tu ôteras ainsi de dessus moi et de dessus la maison de mon père le sang que Joab a répandu sans cause.