2 Samuel 2:13

Joab the son of Zeruiah. — Zeruiah was David’s sister (1 Chronicles 2:16), and Joab the most prominent of her three distinguished sons. Subsequently, by his successful leading of the forlorn hope in the siege of Jerusalem (1 Chronicles 11:6; comp. 2 Samuel 5:8), he became permanently established as commanaer-in-chief of David’s army. He was undoubtedly among “the brethren of David” who came down to him at the cave of Adullam (1 Samuel 22:1), though he is not mentioned by name, like his brother Abishai (1 Samuel 26:6), in the narrative of David’s outlawry.

The pool of Gibeon is a large reservoir or tank, arranged to store the overflow from a subterranean reservoir fed by a spring in the rocky hill-side. Its ruins still remain, about 120 feet long by 100 broad. The hostile forces halted in full sight of each other on the opposite sides of the pool.