John Gill Commentary Numbers 14:45

"Then the Amalekite came down, and the Canaanite who dwelt in that mountain, and smote them and beat them down, even unto Hormah." — Numbers 14:45 (ASV)

Then the Amalekites came down
The hill; met the Israelites as they ascended: and the Canaanites which dwelt in that hill; the same with the Amorites, one of the seven nations of Canaan, (Numbers 13:29);

and smote them ;
with the sword, having the advantage of them in coming down the hill upon them:

and discomfited them even unto Hormah ;
the name of a place, so called from what happened there; as Jarchi says; either from this destruction of the Israelites at this time by these their enemies, or from the destruction of the Canaanites by Israel, (Numbers 21:4); and so here has its name by anticipation; or it may be from both these events, and seems to be confirmed by a third of the like kind, having been in former times called Zephath, (Judges 1:17); see (Joshua 15:30); though some take it to be an appellative here, and not the proper name of a place, and render it even unto destruction, as the Targum of Jonathan, denoting the very great destruction and havoc that were made among them: how many were destroyed is not certain; the judgment threatened them of God soon began to take place, that their carcasses should fall in that wilderness.