2 Samuel 2:15-23 - The battle was very fierce

2:15-17

So there were twelve men from each side. The fight was rather pointless. Each opponent grabbed the other by the head and stabbed them, so all twenty four of the men died. The purpose of the fight was presumably to avoid a major battle, it manifestly failed to do this. A major battle ensued and the Israelites were defeated by David’s men.

2:18-23

Asahel was one of Joab’s brothers and was very fast on his feet. He went chasing after Abner. Abner recognised who was chasing him. He wanted to avoid killing Asahel because he knew the effect that that would have on Joab. So he urges Asahel to give up the chase. Asahel was as head strong as his brother Joab and refused. Abner then had no choice but to kill Asahel.