They had gone as far as the big rock at Gibeon when Amasa caught up with them. Joab had a dagger strapped around his waist over his military uniform, but it fell out as he started towards Amasa.
When Abner returned to Hebron, Joab pretended he wanted to talk privately with him. So he took Abner into one of the small rooms that were part of the town gate and stabbed him in the stomach. Joab killed him because Abner had killed Joab's brother Asahel.
Solomon, don't forget what Joab did to me by killing Abner son of Ner and Amasa son of Jether, the two commanders of Israel's army. He killed them as if they were his enemies in a war, but he did it when there was no war. He is guilty, and now it's up to you to punish him
Gilead is terribly sinful and will end up ruined. Bulls are sacrificed in Gilgal on altars made of stones, but those stones will be scattered in every field.
Listen, you priests! Pay attention, Israel! Listen, you members of the royal family. Justice was your duty. But at Mizpah and Mount Tabor you trapped the people.