Answer
After King Saul’s death, Abner, the commander of Saul’s army, appointed Saul’s son Ish-Bosheth as king over the regions of Israel known as Gilead, Ashuri, Jezreel, Ephraim, and Manasseh “and made him king over Gilead, and over the Ashurites, and over Jezreel, and over Ephraim, and over Benjamin, and over all Israel.”, (2 Samuel 2:9). Ish-Bosheth was 40 years old at the time and ruled for two years “Ish-bosheth, Saul’s son, was forty years old when he began to reign over Israel, and reigned two years. But the house of Judah followed David.”, (2 Samuel 2:10).
During this period, David was king over the tribe of Judah in Hebron, a city in southern Israel. David’s men and Abner’s men engaged in battle. After approximately two years, King Ish-Bosheth accused Abner of having relations with Saul’s concubine “And Saul had a concubine, named Rizpah, the daughter of Aiah: and Ish-bosheth said to Abner, Why have you gone in unto my father’s concubine?”, (2 Samuel 3:7). Angered by the false accusation, Abner vowed to hand over all of Israel to David (2 Samuel 3:8-10).
Abner arranged a meeting with David and reached an agreement to unite the entire nation of Israel under David’s rule. Subsequently, Joab, David’s army commander, confronted David and accused Abner of deceit. According to Joab, Abner was plotting against David. Acting without David’s consent, Joab pursued Abner and killed him (2 Samuel 3:26-27). This act went beyond mere betrayal.
Of supposed loyalty to David, however, Joab had been seeking to avenge his brother Asahel’s death at the hands of Abner (2 Samuel 2:19-23).
David made all of his people mourn and declared that he had nothing to do with Abner’s death. Joab had been acting on his own. However, when Ish-Bosheth heard that Abner had died, he and all Israel were troubled. Two men named Rechab and Baanah came to Ish-Bosheth’s home “at about the heat of the day.” King Ish-Bosheth “was lying on his bed at noon. And they came there, all the way into the house, as though to get wheat, and they stabbed him in the stomach” (2 Samuel 4:5-6). The assassins then cut off Ish-Bosheth’s head and slipped away «For when they came into the house, he lay on his bed in his bedchamber, and they smote him, and slew him, and beheaded him, and took his head, and gat them away through the plain all night. », (2 Samuel 4:7).
Rekab and Baanah brought the head of Ish-Bosheth to David, hoping for a reward. Instead, David had them executed because they had “killed an innocent man in his own house and on his own bed” «how much more, when wicked men have slain a righteous person in his own house upon his bed? shall I not therefore now require his blood of your hand, and take you away from the earth? », (2 Samuel 4:11). David also gave orders to bury the head of Ish-Bosheth in the tomb of Abner at Hebron.
This gruesome series of events paved the way for David to transition from leading the tribe of Judah to becoming king over all of Israel. Despite the violence around him, David remained innocent of the blood of his rivals. After Ish-Bosheth’s and Abner’s murders, David remained in Hebron for five more years.Till the elders of Israel approached him and entered into a covenant to set him as the king of all Israel (2 Samuel 5:1-5). During that period, David and his soldiers captured Jerusalem, establishing it as the capital of Israel and the “City of David.” David governed from Jerusalem for the rest of his 40-year reign.