Nehemiah 13:1-3

On that day they read from the Book of Moses in the hearing of the people, and in it was found written that no Ammonite or Moabite should ever come into the assembly of God, because they had not met the children of Israel with bread and water, but hired Balaam against them to curse them. However, our God turned the curse into a blessing. So it was, when they had heard the Law, that they separated all the mixed multitude from Israel.