Joshua the son of Nun called the priests, and said to them, Take up the ark of the covenant, and let seven priests bear seven trumpets of rams' horns before the ark of Yahweh.
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.