Nehemiah 13:1-3 RSV

1 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 enter the assembly of God;
2 for they did not meet the children of Israel with bread and water, but hired Balaam against them to curse them--yet our God turned the curse into a blessing.
3 When the people heard the law, they separated from Israel all those of foreign descent.