Now Balak son of Zippor saw all that Israel had done to the Amorites,
The children of Israel have at length finished their wanderings in the wilderness, out of which they went up (Num 21:18), and are now encamped in the plains of Moab near Jordan, where they continued till they passed through Jordan under Joshua, after the death of Moses. Now we have here, I. The fright which the Moabites were in upon the approach of Israel, Num 22:2-4.
Commenting on Numbers 22:1-14
And Balak the son of Zippor saw all that Israel had done to the Amorites. The word "Amorites" being particularly pointed, shows, as Aben Ezra observes, that Sihon and Og are both meant, and that there were not among the kings of the land of Canaan any so great as they; wherefore when Balak, who was the present king of Moab, saw what Israel had...
Balak--that is, "empty." Terrified (Deu 2:25; Exo 15:15) at the approach of so vast a multitude and not daring to encounter them in the field, he resolved to secure their destruction by other means.