Matthew Poole and continuators on Judges 11:13

13 And the king of the children of Ammon answered unto the messengers of Jephthah, Because Israel took away my land , when they came up out of Egypt, from Arnon even unto Jabbok, and unto Jordan: now therefore restore those lands again peaceably.

i. e. This Land of Gilead, which was mine, but unjustly taken from me, by Sihon and Og, the Kings of the Amorites; and the injury perpetuated by Israel's detaining it from me. This Land, before the Conquests of Sihon and Og, belonged partly to the Ammonites, as is affirmed, Ios. 13. 25. and partly, and principally, to the Moabites, as appears from Numb. 21. 24, 26. Deut. 3. 11. And indeed, Moab and Ammon did for the most part join their Interests and their Forces, as appears from Scripture-Story; and as Balak the King of the Moabites acted for the Ammonites, so now the King of Ammon seems to act for the Moabites, either as being now his Subjects; or, as his Confederates; whence it comes to pass that Moab and Ammon are here promiscuously mentioned, as v. 15, 17, 18, 25. and Chemosh the known god of the Moabites, Numb. 21. 29. 1 King. 11. 33. 2 King. 23. 13. Ier. 48. 13, 46. is here called the god of the Ammonites, v. 24. though to speak strictly, Moloch or Milchom was their god, 1 King. 11. 5, 7, 33. and 2 King. 23. 13.

Marginal references: Numb. 21. 13.