Moses
Numbers 22:13ESV·traditional attribution

So Balaam rose in the morning and said to the princes of Balak, “Go to your own land, for the LORD has refused to let me go with you.”

Matthew Henry Presbyterian @wholebiblehenry

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

John Gill Reformed Baptist @doctorgill

And Balak sent yet again princes more, and more honourable than they. More in number, and greater in quality, princes of the first rank in his court; supposing that Balaam thought he was not treated with respect enough, they being princes of the meaner sort, and but few, that were sent unto him before, which he imagined was the reason, at least one reason, why...

Jamieson-Fausset-Brown Reformed @jfbcommentary

the Lord refuseth to give me leave to go with you--This answer has an appearance of being good, but it studiously concealed the reason of the divine prohibition [Num 22:12], and it intimated his own willingness and desire to go--if permitted. Balak despatched a second mission, which held out flattering prospects, both to his avarice and his ambition (Gen 31:30).