Matthew Poole and continuators on Joshua 6:25

25 And Joshua saved Rahab the harlot alive , and her fathers houshold, and all that she had: and she dwelleth in Israel even unto this day, because she hid the messengers which Joshua sent to spy out Jericho.

For that general commanding of rooting out the Canaanites seems to have had some exception, in case any of them had sincerely and seasonably cast off their Idolatry and Wickedness, and submitted themselves to the Israelites, as we shall see hereafter.