Verse 20 provides the theological justification for the wholesale massacre of the people: the Lord “hardened their hearts” (see Revised Standard Version), that is, made them proud and stubborn (Good News Translation determined to fight). Again the Hebrew verb condemned to total destruction is used, and it is said that this was done in obedience to the Lord’s command to Moses.

Many languages will have idiomatic expressions equivalent to “harden their hearts” of the Hebrew; for example, “stiffen their necks” or “make their eyes glare.” If idiomatic expressions do exist, then one will have to decide whether it is more effective to introduce an indigenous idiom or to translate in plain language, without a metaphor, as in Good News Translation.

So that they would be condemned to total destruction and all be killed without mercy may be changed to an active construction and translated as a separate sentence: “He did this so that the people of Israel would condemn them to total destruction and kill them all without mercy.”

This was what is somewhat ambiguous in Good News Translation. It actually refers only to the clause which begins so that; it does not refer back to the entire previous sentence. One may translate “The LORD had commanded Moses to kill all the people of the land.”

Quoted with permission from Bratcher, Robert G. and Newman, Barclay M. A Handbook on Joshua. (UBS Helps for Translators). New York: UBS, 1983. For this and other handbooks for translators see here .