Deuteronomy 23:3
"An Ammonite or Moabite shall not enter into the congregation of the LORD; even to their tenth generation shall they not enter into the congregation of the LORD for ever:"
Cross References (ranked by relevance)
In those days also saw I Jews that had married wives of Ashdod, of Ammon, and of Moab:
And the kinsman said, I cannot redeem it for myself, lest I mar mine own inheritance: redeem thou my right to thyself; for I cannot redeem it.
Now Tobiah the Ammonite was by him, and he said, Even that which they build, if a fox go up, he shall even break down their stone wall.
Neither let the son of the stranger, that hath joined himself to the LORD, speak, saying, The LORD hath utterly separated me from his people: neither let the eunuch say, Behold, I am a dry tree.
But it came to pass, that when Sanballat, and Tobiah, and the Arabians, and the Ammonites, and the Ashdodites, heard that the walls of Jerusalem were made up, and that the breaches began to be stopped, then they were very wroth,