David's commanders, Amasa and Joab, were opposites though both were David's nephews. Amasa was promoted to commander even though he lost the only battle he was known to lead. Joab was a successful commander credited with many victories including the capture of Jerusalem. The two men crossed paths while David was trying to prevent Sheba from organizing a rebellion.
AMASA. When the men of the northern tribes became frustrated with the men of Judah, Sheba had convinced them to return to their homes, but he had not yet organized a rebellion. David wished to prevent Sheba from organizing any resistance, so he said to Amasa, his newly appointed commander, "Summon the men of Judah to come to me within three days, and be here yourself." Amasa, however, was negligent. He failed both to gather the army in three days and to report to David. David could not afford further delay, so he sent Abishai to pursue Sheba after putting him at the head of Joab's men and his own personal bodyguard.
JOAB. Joab was a shrewd man always on guard and ever protective of his own interests. He was inclined to treachery from the beginning of his career to the end. Years earlier while pretending to greet Abner, he had stabbed him in the belly to avenge the death of his brother whom Abner had slain in battle (2 Samuel 3:27). Joab had been a co-conspirator with David in deserting Uriah, one of David's mighty men, in the heat of battle so that the enemy might kill him (2 Samuel 11:14-17). More recently, Joab had ignored David's plea to deal gently with Absalom, and slew him while he hung helplessly from a tree (2 Samuel 18:14). In response, David had demoted Joab and replaced him with Amasa, making them rivals.
THE ENCOUNTER. Amasa joined Abishai's forces at Gibeon where he met Joab, who harbored malice in his heart for the man who had replaced him at the head of the army. Unlike Joab, Amasa was not wary or vigilant. In fact, he might even be called gullible. He was not suspicious when Joab dropped a dagger and picked it up with his left hand. He was not wary when Joab took hold of his beard with his right hand to give him a friendly kiss. While kissing Amasa, Joab stabbed him in the belly and then left him to die while writhing in his own blood. This act of treachery nearly stalled the pursuit of Sheba. All who saw Amasa wallowing in his own blood stopped. They could not help Amasa, but they could not abandon him either. Finally, a soldier drug Amasa off the road and covered him with a garment so the pursuit could continue. David, however, would not forget what Joab had done (1 Kings 2:5-6). From this time on, Joab was living on borrowed time.
A malicious man disguises himself with his lips, but in his heart he harbors deceit. Though his speech is charming, do not believe him, for seven abominations fill his heart. His malice may be concealed by deception, but his wickedness will be exposed in the assembly.
-- Proverbs 26:24-26
