Deuteronomy 1:19-21

And when we departed from Horeb, we went through all that great and terrible wilderness, which ye saw by the way of the mountain of the Amorites, as the LORD our God commanded us; and we came to Kadesh-barnea.

We went through all that great and terrible wilderness - of Paran, which included the desert and mountainous space lying between the wilderness of Shur westward, or toward Egypt, and mount Seir, or the land of Edom, eastward; between the land of Canaan northwards, and the Red Sea southward; and thus it appears to have comprehended really the wilderness of Sin and Sinai (Fisk). It was not the whole desert, but only a part of it; because it is observable that it did not commence at Horeb, but only after the Israelites had departed from Horeb. The reference here is to that sterile and inhospitable region east of the Seir mountain range, on the border of which, where it blends with the desert of Arabia, the Israelites were under a necessity of marching in the concluding stages of their journey (cf. Jeremiah 2:6).

Verse 20. I said unto you, Ye are come unto the mountain of the Amorites. The name of the Amorites is used here for the whole population of Canaan; and indeed the Canaanites and Amorites are frequently interchanged (Genesis 15:16; Deuteronomy 20:19; Joshua 3:10; Amos 2:9).