After bitterly denouncing Da'vid for being deceived by a cunning plotter, Jo'ab sent messengers to Ab'ner with the request that he return for a conference. This invitation may have been sent in the name of the king, for it aroused no suspicion in the mind of Ab'ner. He promptly came back to the capital, where Jo'ab took him aside under the pretense of a private conversation, and thereupon assassinated him. Jo'ab tried to justify this cruel deed as an act of revenge for the death of his brother As'a-hel, and by the claim that Ab'ner was a traitor to Da'vid and an enemy of GOD, but few believed that this was his real motive.
Da'vid's sense of justice was outraged by the treachery of Jo'ab, and he felt that the proposed alliance of the rebellious tribes with his kingdom would be greatly hampered by this cruel deed. He disclaimed all responsibility for the act of his general, pronouncing a curse upon Jo'ab and his family. As a token of honor for the slain Ab'ner he proclaimed a season of mourning, and himself took part in the lamentations. In his funeral dirge he declared:
"Ab'ner died, not as a worthless man, nor as one guilty of any crime worthy of death; he was overpowered without suspecting evil, and was murdered as a defenseless hero. A prince and a great man has fallen this day in Is'ra-el."
Da'vid's lament at the grave of Ab'ner and his fair-minded praise won him the increased support of all Is'ra-el, and the union of all the tribes was quickened rather than delayed by the tragedy.
When the news of Ab'ner's death reached Ish-bo'sheth, this weak king lost all courage to keep on as a rival of Da'vid, and his followers lost hope of maintaining their separate government. The military group which had been the chief support of the puppet king became disorganized, and treason broke out among the officers.
Two of the rebellious officers treacherously murdered Ish-bo'sheth while he was quietly resting on his bed. With the hope of gaining a reward they cut off the head of their master and brought it to Da'vid. Like the Am'a-lek-ite who claimed to have slain Saul at his own request, these men failed to grasp the nobility of Da'vid, and were denounced for their wicked deed. Da'vid ordered their immediate execution, and gave instructions for an honorable burial of the head of Ish-bo'sheth.
Even though these men had paid for their treachery with their lives, the death of the puppet king removed the last barrier to a united nation. The princes of all the tribes of Is'ra-el which had previously rejected the rule of Da'vid, and had allied with Ab'ner in his effort to establish the weak Ish-bo'sheth firmly on the throne of Is'ra-el, now came to He'bron to offer Da'vid the homage of all the nation. After seven years of civil war, during which he had been acknowledged as king only by the tribe of Ju'dah, Da'vid was now the ruler of all the twelve tribes, and Is'ra-el entered upon a period of great prosperity.
