Seven priests shall bear seven trumpets of rams' horns before the ark: and the seventh day you shall compass the city seven times, and the priests shall blow the trumpets.
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.