Deuteronomy 23:7 "You must never seek their peace nor their prosperity all your days, forever"

The nations of Ammon and Moab are to be totally rejected.

As we mentioned above (Negative Mitzvah 53), the Torah explains that their very nature is cruel.

When the Jewish people were on their way out of Egypt, they did not offer any hospitality or answer requests for even a bit of bread and water. Additionally, they hired Balaam to curse the Jewish people.

This Negative Mitzvah concerns war with Ammon or Moab.

In general, we are commanded to offer the opportunity of peaceful surrender to enemy cities in times of war. However, this offer of peace may not be made to Ammon and Moab.