Then Abner looked behind him and said, “Is it you, Asahel?” And he answered, “It is I.”
We have here the contest between Abner and Asahel. Asahel, the brother of Joab and cousin-german to David, was one of the principal commanders of David's forces, and was famous for swiftness in running: he was as light of foot as a wild roe (Sa2 2:18); this he got the name of by swift pursuing, not swift flying.
Commenting on 2 Samuel 2:18-24
Then Abner looked behind him,.... Perceiving one at his heels, and making haste up to him. And said, art thou Asahel? for it seems he knew him personally, being well acquainted with his family: and he answered, I am; so that they were very near to each other, as to discourse together, and be heard and understood by each other.
2Sa 2:20-22 Then Abner turned round, asked him whether he was Asahel, and said to him, “Turn to thy right hand or to thy left, and seize one of the young men and take his armour for thyself,” i.e., slay one of the common soldiers, and take his accoutrements as booty, if thou art seeking for that kind of fame. But Asahel would not turn back from Abner.
Commenting on 2 Samuel 2:20-22