Numbers 22:31-35
31 Then the Lord opened Balaam’s eyes, and he saw the Angel of the Lord standing in the way with His drawn sword in His hand; and he bowed his head and lay himself face down.
32 The Angel of the Lord said to him, “Why have you struck your donkey these three times? Behold, I have come out to stand against you, because your behavior was obstinate and contrary to Me.
33 The donkey saw Me and turned away from Me these three times. If she had not turned away from Me, I would have certainly killed you now, and let her live.”
34 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. But now, if my going displeases You, I will turn back.”
35 The Angel of the Lord said to Balaam, “Go with the men, but you shall speak only what I tell you.” So Balaam went along with the leaders of Balak.