David regretted Abner's death, wept at Abner's grave, and lamented for him (vv. 28-39).
While all the events recorded in these chapters were taking place, God was present in His sovereignty behind the scene. After Saul's death only one tribe—Judah—was loyal to David. David was crowned by the tribe of Judah, but Ish-bosheth rivaled him in the kingship, and there was war between the house of David and the house of Saul. Everything that happened was in David's favor. He did not do anything; rather, he was simply the enjoyer on the throne.
I wish to emphasize the fact that behind all the details concerning the house of David and the house of Saul, God was there in His sovereignty. God was behind the scene to direct the situation so that it would turn out in favor of David.
God's intention was to terminate the house of Saul. Saul had four sons. Three went to the war with Saul and were killed with him in the battle. Ish-bosheth was spared, but he was killed within two years, ending Saul's family. When the nursing mother of Saul's grandson, Mephibosheth, heard the news that Saul and Jonathan were dead in the war, she ran with the little child in her bosom, and he fell down to the ground (4:4). As a result, he became crippled. Thus, in a short time God terminated the entire family of Saul, leaving just one crippled boy as an orphan under the loving care of David, who kept his covenant with Jonathan (1 Sam. 20:14-17; 2 Sam. 9:1-13). We all need to learn a lesson from these illustrations—to fear God and not play with Him.