Why did Joab stab Abner in the stomach?

ANSWER

for killing his brother Asahel

2nd Samuel 3 :

26 Joab then left David and sent messengers after Abner, and they brought him back from the cistern at Sirah. But David did not know it. 27 Now when Abner returned to Hebron, Joab took him aside into an inner chamber, as if to speak with him privately. And there, to avenge the blood of his brother Asahel, Joab stabbed him in the stomach, and he died.
Play Our Bible Trivia Game
Can You Light All 30 Candles?