As God’s king, David was obligated to uphold God’s law in Israel (Deuteronomy 17:18–20). In this case, the law required the death of Joab because he had murdered a fellow Israelite (Genesis 9:6; Exodus 21:12; Leviticus 24:17; Numbers 35:30–31). Since he was not at this point in time in a position to have Joab executed (see 2 Samuel 3:39; 1 Kings 2:5–6), David pronounced a curse upon him. The curse of David is a summary of the curses found for lawbreakers in Leviticus 26:14–39 and Deuteronomy 28:15–68.1 This curse is similar to Samuel’s prophecy regarding the house of Eli (1 Samuel 2:31–36).2
29 Que ce sang retombe sur Joab et sur toute la maison de son père! Qu'il y ait toujours quelqu'un dans la maison de Joab, qui soit atteint d'un flux ou de la lèpre, ou qui s'appuie sur un bâton, ou qui tombe par l'épée, ou qui manque de pain!