C. F. Keil and Franz Delitzsch on Numbers 14:25

Num 14:25

The divine reply to the intercession of Moses terminated with a command to the people to turn on the morrow, and go to the wilderness to the Red Sea, as the Amalekites and Canaanites dwelt in the valley. “The Amalekites,” etc.: this clause furnishes the reason for the command which follows. On the Amalekites, see at Gen 36:12, and Exo 17:8. The term Canaanites is a general epithet applied to all the inhabitants of Canaan, instead of the Amorites mentioned in Deu 1:44, who held the southern mountains of Canaan. “The valley” is no doubt the broad Wady Murreh (see at Num 13:21), including a portion of the Negeb, in which the Amalekites led a nomad life, whilst the Canaanites really dwelt upon the mountains (Num 14:45), close up to the Wady Murreh.