John Gill Commentary Deuteronomy 1:20

"And I said unto you, Ye are come unto the hill-country of the Amorites, which Jehovah our God giveth unto us." — Deuteronomy 1:20 (ASV)

And I said to you, you are come to the mountain of the
Amorites
Which was inhabited by them, and was one of the seven nations the Israelites were to destroy, and possess their land, and which lay on the southern part of the land of Canaan:

which the Lord our God does give to us ;
not the mountain only, but the whole country of that people, and even all the land of Canaan.