Deuteronomy 23:3-4

No Ammonite or Moabite may come into the meeting to worship the LORD, and none of their descendants for ten generations may come in. This is because the Ammonites and Moabites did not give you bread and water when you came out of Egypt. And they hired Balaam son of Beor, from Pethor in Northwest Mesopotamia, to put a curse on you.