2 Samuel 2:15 (KJV)

Ishbosheth Saul's son was forty years old when he began to reign over Israel, and reigned two years. But the house of Judah followed David.

And the time that David was king in Hebron over the house of Judah was seven years and six months.

And Abner the son of Ner, and the servants of Ishbosheth the son of Saul, went out from Mahanaim to Gibeon.

And Joab the son of Zeruiah, and the servants of David, went out, and met together by the pool of Gibeon: and they sat down, the one on the one side of the pool, and the other on the other side of the pool.

And Abner said to Joab, Let the young men now arise, and play before us. And Joab said, Let them arise.

And they caught every one his fellow by the head, and thrust his sword in his fellow's side; so they fell down together: wherefore that place was called Helkathhazzurim, which is in Gibeon.

And there was a very sore battle that day; and Abner was beaten, and the men of Israel, before the servants of David.

And there were three sons of Zeruiah there, Joab, and Abishai, and Asahel: and Asahel was as light of foot as a wild roe.

And Asahel pursued after Abner; and in going he turned not to the right hand nor to the left from following Abner.

Then Abner looked behind him, and said, Art thou Asahel? And he answered, I am.