Verse 13: And the king of the children of Ammon answered unto the messengers of Jephthah, (Num. 21:24-26) Because Israel took away my land, when they came up out of Egypt, from Arnon even unto (Gen. 32:22) Jabbok, and unto Jordan: now therefore restore those lands again peaceably.
[Israel took away my land] Question: Is this true? and how? Response: It is a lie; for at the coming of the Israelites that land belonged to the Amorites, before it belonged to the Moabites, but it never belonged to the Ammonites (Menochius out of Serarius, Junius, Piscator). But if it be so, and the Ammonites never had any right to it, it does not seem like Jephthah would pass over that in silence, and not refute the falseness of the claim (Bonfrerius). Add that the land of Sihon did not belong to the Moabites in its entirety, but partly to the Ammonites (Bonfrerius, Lapide); as it is evident from this passage (Lapide), and from Joshua 13:25 (Bonfrerius). Moreover, the King of Ammon was also the King of Moab (Lyra, Cajetan and Carthusianus in Bonfrerius, Lapide, Bonfrerius), either now, or formerly (Lapide); and on that account he demands back this land. It is confirmed from this, that in this whole dispute several times mention is made of Moab and of Chemosh, the idol of Moab, which he calls the god of the King of the Ammonites, verse 24 (Lapide). Therefore, the King of Ammon treats on behalf of the Moabites, either as his subjects, or as his allies and confederates (Lapide). For the Ammonites and Moabites were generally conjoining their affairs. Also, of that land, which he was calling his own, and of the other of the Moabites, conjoined to his land, the cause was the same and altogether alike (Bonfrerius).
My land, that is, 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, Joshua 13:25; and partly and principally to the Moabites, as appears from Numbers 21:24, 26; Deuteronomy 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 Judges 11:15, 17, 18, 25; and Chemosh, the known god of the Moabites, Numbers 21:29; 1 Kings 11:33; 2 Kings 23:13; Jeremiah 48:13, 46, is here called the god of the Ammonites, Judges 11:24, though, to speak strictly, Moloch or Milcom was their god, 1 Kings 11:5, 7, 33; 2 Kings 23:13.
 Hebrew: וַיֹּאמֶר֩ מֶ֙לֶךְ בְּנֵי־עַמּ֜וֹן אֶל־מַלְאֲכֵ֣י יִפְתָּ֗ח כִּֽי־לָקַ֙ח יִשְׂרָאֵ֤ל אֶת־אַרְצִי֙ בַּעֲלוֹת֣וֹ מִמִּצְרַ֔יִם מֵאַרְנ֥וֹן וְעַד־הַיַּבֹּ֖ק וְעַד־הַיַּרְדֵּ֑ן וְעַתָּ֕ה הָשִׁ֥יבָה אֶתְהֶ֖ן בְּשָׁלֽוֹם׃