Deuteronomy 23:1-6

No eunuch is to enter the congregation of GOD. No bastard is to enter the congregation of GOD, even to the tenth generation, nor any of his children. No Ammonite or Moabite is to enter the congregation of GOD, even to the tenth generation, nor any of his children, ever. Those nations didn’t treat you with hospitality on your travels out of Egypt, and on top of that they also hired Balaam son of Beor from Pethor in Mesopotamia to curse you. GOD, your God, refused to listen to Balaam but turned the curse into a blessing—how GOD, your God, loves you! Don’t even try to get along with them or do anything for them, ever.