Deuteronomy 2:19

As for the younger, she also bore a son and called his name Ben-ammi; he is the father of the sons of Ammon to this day.

“Only you did not go near to the land of the sons of Ammon, all along the river Jabbok and the cities of the hill country, and wherever Yahweh our God had commanded us.

‘Then they went through the wilderness and around the land of Edom and the land of Moab and came to the east toward the sunrise of the land of Moab, and they camped beyond the Arnon; but they did not enter the territory of Moab, for the Arnon was the border of Moab.