Charles Ellicott Commentary 2 Samuel 2:24

"But Joab and Abishai pursued after Abner: and the sun went down when they were come to the hill of Ammah, that lieth before Giah by the way of the wilderness of Gibeon." — 2 Samuel 2:24 (ASV)

The hill of Ammah. —No identification of either Ammah or Giah has yet been made, but as it was by the way of the wilderness of Gibeon, it may be conjectured that it was not far from that town, and hence that the pursuit was not long.