16 However, in the cities of the nations the LORD your God is giving you as an inheritance, do not leave alive anything that breathes.

Read Deuteronomy 20:16 Using Other Translations

But of the cities of these people, which the LORD thy God doth give thee for an inheritance, thou shalt save alive nothing that breatheth:
But in the cities of these peoples that the LORD your God is giving you for an inheritance, you shall save alive nothing that breathes,
In those towns that the LORD your God is giving you as a special possession, destroy every living thing.