Do not harass Moab or contend with them in battle: the meaning is clear enough, but the English is not natural. Revised English Bible is better, “Do not harass the Moabites or provoke them to battle,” or we may say “Do not cause trouble for the people of Moab or make them fight you.” In this context “to harass” means to bother or molest by unprovoked attacks, verbal or physical.

Ar was the capital of Moab (see verse 18; Num 22.36); here it stands for the whole country. This is why Revised Standard Version and Good News Translation translate as Moab.

The sons of Lot are Lot’s descendants, the Moabites (Gen 19.37). This final sentence in some languages may seem to indicate that the sons of Lot are a different people from “the people of Moab.” In such a case we may place this phrase immediately after Moab; for example, “Don’t … with the people of Moab. They are the descendants of Lot, and I have given them…,” or even “The people of Moab are the descendants of Lot, so don’t harass them or make them fight you.”

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .