Charles Ellicott Commentary Joshua 6:17

"And the city shall be devoted, even it and all that is therein, to Jehovah: only Rahab the harlot shall live, she and all that are with her in the house, because she hid the messengers that we sent." — Joshua 6:17 (ASV)

The city shall be accursed. — Hebrew, shall be chêrem, “a devoted or accursed thing”; and so in Joshua 6:18, from the accursed thing. (See Note on Deuteronomy 7:26.) The combination of the two ideas of devotion to God and utter destruction may be seen in the sin offering (Leviticus 6:25), which is called “holy of holies,” or most holy, and yet, when offered for the priest or congregation, must be utterly consumed.