The city shall be devoted, even it and all that is therein, to Yahweh: only Rahab the prostitute shall live, she and all who are with her in the house, because she hid the messengers that we sent.
One result of moral filth is physical disease. Therefore, the destruction of the Canaanites (in some cases together with their sheep and cattle) ensured the removal of deadly diseases that could have threatened Israel’s existence. The absence of Canaanite religious practices would also be a help to Israel’s religious life and moral well-being.