Joshua 9:15 - Joseph Benson’s Commentary on the Old and New Testaments

Joshua made a league with them to let them live Not merely, it seems, to spare their lives, which, supposing them to belong to a far country, they had no warrant to take away, but to let them continue in the enjoyment of their effects; the word life in Scripture being frequently of equal signification with prosperity. That this league was lawful and obliging, appears, 1st, Because Joshua and all the princes, upon the review, concluded it so to be, and spared them accordingly. 2d, Because God punished the violation of it long after, 2 Samuel 21:1. 3d, Because God is said to have hardened the hearts of all other cities, not to seek peace with Israel, that so he might utterly destroy them, (Joshua 11:19-20,) which seems to imply that their utter destruction did not necessarily come upon them by virtue of any peremptory command of God, but by their own obstinate hardness, whereby they refused to make peace with the Israelites.