Albert Barnes Commentary Numbers 23:3

"And Balaam said unto Balak, Stand by thy burnt-offering, and I will go: peradventure Jehovah will come to meet me; and whatsoever he showeth me I will tell thee. And he went to a bare height." — Numbers 23:3 (ASV)

Balaam apparently expected to observe some phenomenon in the sky or in nature, which he would be able, according to the rules of his art, to interpret as a portent. It was for such “auguries” (not as the King James Version “enchantments” (Numbers 23:23)) that he now departed to watch; contrast (Numbers 24:1).

A high place — Or, “A bare place on the hill,” as opposed to the high place with its grove of trees.