Numbers 22:31
Then the LORD opened the eyes of Balaam, and he saw the angel of the LORD standing in the way, and his sword drawn in his hand: and he bowed down his head, and fell flat on his face. Then the LORD opened the eyes of Balaam, and he saw the angel of the LORD standing in the way, and his sword drawn in his hand: and he bowed down his head, and fell flat on his face.
On his presumptuous journey to Moab to meet Balak, Balaam went without being called to overtake the messengers, treating God's further silence as permission after being told not to go, and followed his own inclination and covetous desire for promotion, reward, and honor in trying to please both God and man. Because his way was perverse before God and against the Lord's will and command, God's anger was kindled and His angel stood posted blocking the road to oppose him and to slay and destroy him for his folly. The drawn sword made the danger plain as an example of God using unseen angels to restrain human purposes and protect His people.
The beast he rode saw the angel first and repeatedly turned aside, sparing his life, while Balaam, blinded by passion, rage, and covetousness, did not notice and did not even treat it as remarkable when the beast spoke. When the Lord opened his eyes and removed his blindness, Balaam saw the angel standing in the way with sword drawn, which made the danger plain, and terrified, he left his beast and bowed his head low flat on his face in humility. The angel told him his way was perverse, warned him against gratifying the Moabites, and then gave him permission to go on, so that God might glorify His name before Israel's enemies by showing that even a man of covetous disposition dared not curse Israel for any promises of promotion or rewards, which was important for Israel to overcome the Moabites in order to overcome Canaan.
The angel also stood ready to defend the mistreated animal, for Balaam was cruelly mistreating his animal while acting against God's command and following his own will. The same divine witness stands against cruelty to animals: if their eyes were opened, those who abuse animals would see an angel of God as a witness against them, for God sees such acts, they are recorded in heaven, and cruelty toward animals and resistance to God's will bring accountability and judgment. Balaam worked contrary to God because selfishness and covetousness had entered his plans and he had left God out of his heart, and his story is an example of people becoming hindrances to God's work through their own purposes. Balak led Balaam from one point to another in the vain hope of inducing him to change Israel's blessing into a curse, but the repeated moves could not make him curse what God had blessed, showing that neither human applause nor fear of man can shake a steadfast servant who is sustained by divine power.