'Heirs' in the Bible

Concerning the sons of Ammon. Thus says the Lord:“Does Israel have no sons?Or has he no heirs?Why then has Malcam taken possession of GadAnd his people settled in its cities?

Therefore, behold, the days come, saith the LORD, that I will cause an alarm of war to be heard in Rabbah of the Ammonites; and it shall be a desolate heap, and her daughters shall be burned with fire: then shall Israel be heir unto them that were his heirs, saith the LORD.