Numbers 22:31-32

Then Jehovah opened the eyes of Balaam, and he saw the angel of Jehovah standing in the way, with his sword drawn in his hand; and he bowed his head, and fell on his face. And the angel of Jehovah said unto him, Wherefore hast thou smitten thine ass these three times? behold, I am come forth for an adversary, because thy way is perverse before me