Bible Notes Online - 2-Samuel 2 - ESV
Commentary

Chapters 2-4 cover the 7½ years during which David was king at Hebron. The Lord God had told him to live there. He was king over the tribe of Judah, see 1 Sam 30.26, and 1.18, which refer only to Judah.

v1-4: Initially, David reigned in Hebron, Jerusalem being occupied by the Jebusites. Further, Jerusalem, which would become the capital city of all Israel, belonged to Benjamin, Saul’s tribe.

v5-7: David sent a message of support to the men of Jabesh Gilead, who had recovered Saul's body.

v8-11: Abner and Ishbosheth sought to inherit Saul's crown. Abner was the stronger man, and seems to have used Ishbosheth as a puppet, see 3.11. The two years of Ishbosheth's reign fell during the 7½ years of David's.

v12-18: Abner and Joab brought their respective armies to fight. The battle quickly turned against Abner. This battle reflected the gradual victory of David's forces over Ishbosheth's.

v19-23: Asahel pursued Abner, not turning aside, being single-minded. But that rashness cost him his life. Had he been wiser, he might have lived.

v24-28: Abner managed to gather his army on a hilltop, from where he addressed Joab. His argument seems to be that it is folly for brothers to fight each other. Joab halted his pursuit.

v29-32: Abner escaped across the Jordan to Mahanaim. Joab returned to David at Hebron. The victory had been clear, Joab had lost only 20, compared to Abner's 360.