Numbers 22:31-35

Then the Lord opened Balaam’s eyes, and he saw the angel of the Lord standing in the way with his sword drawn in his hand; and he bowed all the way to the ground.

Then the angel of the Lord said to him, “Why have you struck your donkey these three times? Behold, I have come out as an adversary, because your way was reckless and contrary to me.

But the donkey saw me and turned away from me these three times. If she had not turned away from me, I certainly would have killed you just now, and let her live.”

So Balaam said to the angel of the Lord, “I have sinned, for I did not know that you were standing in the way against me. Now then, if it is displeasing to you, I will turn back.”

But the angel of the Lord said to Balaam, “Go with the men, but you shall speak only the word that I tell you.” So Balaam went along with the representatives of Balak.