Albert Barnes Commentary Deuteronomy 1:7

"turn you, and take your journey, and go to the hill-country of the Amorites, and unto all [the places] nigh thereunto, in the Arabah, in the hill-country, and in the lowland, and in the South, and by the sea-shore, the land of the Canaanites, and Lebanon, as far as the great river, the river Euphrates." — Deuteronomy 1:7 (ASV)

To the mount of the Amorites - that is, to the mountain district occupied by the Amorites, reaching into the Negeb, and part of the territory assigned to the tribe of Judah.