Numbers 22:8

And he said unto them, Lodge here this night, and I will bring you word again, as the Lord shall speak unto me, for he knew that the God of Israel was the true God and feared to do anything contrary to His will. And the princes of Moab abode with Balaam. The false prophet was merely trying to put off the time when he must refuse, since he knew that the Lord would never consent to a curse upon His people, but also since the reward in the hands of the messengers was a powerful argument to his avaricious soul.