Deuteronomy 20:16-18

Young's Literal Translation

¹⁶ `Only, of the cities of these peoples which Jehovah thy God is giving to thee [for] an inheritance, thou dost not keep alive any breathing;

¹⁷ for thou dost certainly devote the Hittite, and the Amorite, the Canaanite, and the Perizzite, the Hivite, and the Jebusite, as Jehovah thy God hath commanded thee,

¹⁸ so that they teach you not to do according to all their abominations which they have done to their gods, and ye have sinned against Jehovah your God.