וַנֵּ֣פֶן וַנַּ֔עַל דֶּ֖רֶךְ הַבָּשָׁ֑ן וַיֵּצֵ֣א עוֹג֩ מֶֽלֶךְ־הַבָּשָׁ֨ן לִקְרָאתֵ֜נוּ ה֧וּא וְכָל־עַמּ֛וֹ לַמִּלְחָמָ֖ה אֶדְרֶֽעִי׃
Then we turned, and went up the way to Bashan; and Og the king of Bashan came out against us, he and all his people, unto battle at Edrei.
Rashi on Deuteronomy
ונפן ונעל AND WE TURNED AND WENT UP — every journey towards the north (from the wilderness towards Canaan) is “uphill”.
Rav Hirsch on Torah
Kap. 3. V. 1. ונפן. Abweichend von dem ammonitischen Gebiete. ׳ויצא וגו Daher ward ihm kein Friedensangebot gesandt (רמב׳׳ן).
Chizkuni
ונפן ונעל, “we turned around and ascended; from the south to the north.”