John Gill Commentary 2 Samuel 2:20

"Then Abner looked behind him, and said, Is it thou, Asahel? And he answered, It is I." — 2 Samuel 2:20 (ASV)

Then Abner looked behind him
Perceiving one at his heels, and making haste up to him.

And said, are you 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.