Joab stabs General Amasa with a dagger after inviting him over for a “friendly” chat, in this stained glass window from the choir of St. Thomas Church in Strasbourg, France. Throughout his career, Joab engages in violent dirty tricks to secure his own position at court. In this instance, he is trying to regain his job as commander of Israel’s army, after having been fired by David and replaced by Amasa. But like his other acts of violence, this murder is a good thing for David too: Amasa had proved disastrously incompetent, and it is only with Joab in charge of the army, quelling any and all rebellions, that David can hold onto the throne.