An Amalekite comes to tell David of Saul's death, and gives Saul's crown to David.
David mourns for Saul's death, and kills the Amalekite who admits finishing Saul off.
(David begins to assume the kingship, here. You may not command capital punishment unless you are the king.)
David moves back to Israel, to Hebron, and the elders of Judah anoint him king.
But Saul's commander anoints Saul's son Ish-bosheth king over the rest of Israel. Uh-oh.
Violence breaks out. Abner kills David's nephew Asahel, but only 18 others. Israel loses 360.
How this is about Jesus
His anointing as king of Israel was also challenged. Violence resulted.
But Jesus did not pick up the sword - His anointing was to a different purpose.
There are times to fight, even with God's people, to maintain God's purpose among His people. Horrifying and distressing, but also necessary.
"How the mighty have fallen!" - 2 Sam. 1:19