וַיִּ֣ירְשׁ֔וּ אֵ֖ת כָּל־גְּב֣וּל הָאֱמֹרִ֑י מֵֽאַרְנוֹן֙ וְעַד־הַיַּבֹּ֔ק וּמִן־הַמִּדְבָּ֖ר וְעַד־הַיַּרְדֵּֽן׃
And they possessed all the border of the Amorites, from the Arnon even unto the Jabbok, and from the wilderness even unto the Jordan.
Rashi on Judges
They took possession, etc., from Arnon to the Yabok. Which you claim as yours, they annexed from Sichon.
Rashi on Judges
From the wilderness to the Yardein. There was a wilderness area adjoining the Yardein.