The men said to her, Our life for yours, if you don't utter this our business; and it shall be, when Yahweh gives us the land, that we will deal kindly and truly with you.
"Utterly destroyed" translates the Hebrew herem, a technical term for the practice of completely destroying the spoils of war as a way of consecrating them to a deity (cf. Joshua 6:17). [Note: Madvig, p. 262.] 