What does Amos 2:12 mean?

Yet I destroyed the Amorite before them, whose height was like the height of the cedars, and he was strong as the oaks; yet I destroyed his fruit from above, and his roots from beneath.

Also I brought you up out of the land of Egypt, and led you forty years in the wilderness, to possess the land of the Amorite.

I raised up some of your sons for prophets, and some of your young men for Nazirites. Isn’t this true, you children of Israel?” says Yahweh.

Behold, I will crush you in your place, as a cart crushes that is full of grain.

Flight will perish from the swift; and the strong won’t strengthen his force; neither shall the mighty deliver himself;

neither shall he stand who handles the bow; and he who is swift of foot won’t escape; neither shall he who rides the horse deliver himself;