Deuteronomy 23:3-8

3An Ammonite or Moabite shall not enter into the congregation of Yhwh; even to their tenth generation shall they not enter into the congregation of Yhwh for ever: 4Because they met you not with bread and with water in the way, when ye came forth out of Egypt; and because they hired against thee Balaam the son of Beor of Pethor of Mesopotamia, to curse thee. 5Nevertheless Yhwh thy God would not hearken unto Balaam; But Yhwh thy God turned the curse into a blessing unto thee, because Yhwh thy God loved thee. 6Thou shalt not seek their peace nor their prosperity all thy days for ever.1

7Thou shalt not abhor an Edomite; for he is thy brother: thou shalt not abhor an Egyptian; because thou wast a stranger in his land. 8The children that are begotten of them shall enter into the congregation of Yhwh in their third generation.