Numbers 22:8-9, 31-35

He said to them, “Spend the night here, and I will bring word back to you as the LORD may speak to me.” And the leaders of Moab stayed with Balaam. Then God came to Balaam and said, “Who are these men with you?”

Then the LORD opened the eyes of Balaam, and he saw the angel of the LORD standing in the way with his drawn sword in his hand; and he bowed all the way to the ground. 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 contrary to me. But the donkey saw me and turned aside from me these three times. If she had not turned aside from me, I would surely have killed you just now, and let her live.” 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 which I tell you.” So Balaam went along with the leaders of Balak.