Judges 11:13, 22

And the king of the people of Ammon answered the messengers of Jephthah, “Because Israel took away my land when they came up out of Egypt, from the Arnon as far as the Jabbok, and to the Jordan. Now therefore, restore those lands peaceably.”

They took possession of all the territory of the Amorites, from the Arnon to the Jabbok and from the wilderness to the Jordan.