New Revised Standard Version
The king of the Ammonites answered the messengers of Jephthah, “Because Israel, on coming from Egypt, took away my land from the Arnon to the Jabbok and to the Jordan; now therefore restore it peaceably.”

Contemporary English Version
The king of Ammon replied, "Tell Jephthah that the land really belongs to me, all the way from the Arnon River in the south, to the Jabbok River in the north, and west to the Jordan River. When the Israelites came out of Egypt, they stole it. Tell Jephthah to return it to me, and there won't be any war."

New American Bible
The king of the Ammonites answered the messengers of Jephthah, “Israel took away my land from the Arnon to the Jabbok and the Jordan when they came up from Egypt. Now restore it peaceably.”

Douay-Rheims Bible
And he answered them: Because Israel took away my land, when he came up out of Egypt, from the confines of the Arnon unto the Jaboc and the Jordan: now, therefore, restore the same peaceably to me.

And he answered them: Because Israel took away my land, when he came up out of Egypt, from the confines of the Arnon unto the Jaboc and the Jordan: now, therefore, restore the same peaceably to me.

Because Israel

Numbers 21:24-26 And he was slain by them with the edge of the sword, and they possessed his land from the Arnon unto the Jeboc, and to the confines of the children of Ammon: for the borders of the Ammonites, were kept with a strong garrison. . . .

Proverbs 19:5,9 A false witness shall not be unpunished: and he that speaketh lies, shall not escape. . . .

from Arnon.

Genesis 32:22 And rising early, he took his two wives and his two handmaids, with his eleven sons, and passed over the ford of Jaboc.

Deuteronomy 2:37 Except the land of the children of Ammon, to which we approached not: and all that border upon the torrent Jeboc, and the cities in the mountains, and all the places which the Lord our God forbade us.

Deuteronomy 3:16 And to the tribes of Ruben and Gad I gave of the land of Galaad as far as the torrent Arnon, half the torrent, and the confines even unto the torrent Jeboc, which is the border of the children of Ammon: