John Gill Commentary Numbers 22:9

"And God came unto Balaam, and said, What men are these with thee?" — Numbers 22:9 (ASV)

And God came to Balaam
In a dream very probably, as he did to Abimelech and Laban, (Genesis 20:3) (31:24) :

and said, what men are these with you ?
who lodged with him that night. This he said, not as ignorant who they were, or from where they came, or what they came about; but in order to lead on to a discourse with Balaam, and to have from him the account of the men, and their business, and to try his fidelity in relating the affair.