Numbers 22:22 - The Popular Commentary by Paul E. Kretzmann

And God's anger was kindled because he (Balaam) went, because he was going with a blind and dogged determination to carry out his own plan and to obtain the promised reward. And the Angel of the Lord, the Son of God, who, as so often in the Old Testament, assumed this form, v. 35, stood in the way, in the road on which he journeyed to the country of the Midianites and the Moabites, for an adversary against him, to cause him to come to his senses even at this stage. Now he was riding upon his ass, and his two servants were with him.