And Joab said - The meaning of this verse appears to be this: If Abner had not provoked the battle, (see 2 Samuel 2:14;), Joab would not have attacked the Israelites that day; as his orders were probably to act on the defensive. Therefore the blame fell upon Israel.
Joab‘s speech means either “unless thou hadst spoken (challenged us to fight, 2 Samuel 2:14), the people would have returned from the pursuit of their brethren (many hours ago, even) this morning;” or, “If thou hadst not spoken (asked for peace, 2 Samuel 2:26), surely the people would have returned, etc., in the morning, i. e. would not have ceased the pursuit until the morning.” The latter interpretation is the more accordant with Joab‘s boastful character.