John Calvin Commentary Numbers 23:26

"But Balaam answered and said unto Balak, Told not I thee, saying, All that Jehovah speaketh, that I must do?" — Numbers 23:26 (ASV)

But Balaam answered and said. The mercenary prophet here confesses that he has no more power of his own to be silent than to speak. Nor is there any doubt that he would excuse himself with servility to the proud king, to whom he would willingly have sold himself, as if, in his desire to avert the hatred and blame from himself, he would state that he was carried away against his will by the Divine impulse. At the same time, he throws back the blame on Balak himself, who, though warned in time, had still foolishly sent to fetch him. The rest I have already expounded.