Adam Clarke on Joshua 23:3

For the Lord your God is he that hath fought for you - There is much both of piety and modesty in this address. It was natural for the Israelites to look on their veteran, worn-out general, who had led them on from conquest to conquest, with profound respect; and to be ready to say, "Had we not had such a commander, we had never got possession of this good land." Joshua corrects this opinion, and shows them that all their enemies had been defeated, because the Lord their God had fought for them. That the battle was the Lord's, and not his; and that God alone should have the glory.