Numbers 22:27
And when the ass saw the angel of the LORD, she fell down under Balaam: and Balaam’s anger was kindled, and he smote the ass with a staff. And when the ass saw the angel of the LORD, she fell down under Balaam: and Balaam’s anger was kindled, and he smote the ass with a staff.
The verse occurs as Balaam went to overtake Balak's ambassadors on his way to curse Israel after God did not forbid his going the second time, yet God's anger was kindled against him because he went. The angel of the Lord was sent to stand in the way to withstand Balaam because his way was perverse before him, ready with a flaming sword to slay him for his presumptuous folly. The ass saw the angel, turned aside in terror, refused to go forward, and fell down under Balaam, and by doing so protected Balaam from being slain.
Balaam was blind to the divine messenger obstructing his path, beside himself with rage and blinded by passion, so he struck and beat the ass with his staff and failed to recognize what the animal saw, not noticing anything remarkable even when the beast spoke because passion had clouded his judgment. When the angel revealed himself, Balaam was terrified, left his beast, and bowed in humility before him. The angel told Balaam he had come out to withstand him, warned him against gratifying the Moabites, and spoke in defense of the mistreated animal, indignant at his cruelty.
The angel then gave Balaam permission to pursue his journey so God could glorify His name before the enemies of Israel by showing that a man of covetous disposition dared not pronounce a curse against Israel for any promises of promotion or rewards. The encounter shows that God can use unseen angels to confront and restrain those set on doing harm. The episode shows that God sees cruelty to animals and holds people accountable for it, condemning it; a merciful person is merciful to his beast.
The verse illustrates working contrary to God, warning that like Balaam people bring selfishness and covetousness into God's work while leaving God out of their hearts and plans. In the broader account, Balak's conducting Balaam from one point to another in the vain hope of changing Israel's blessing into a curse could not change the blessing, illustrating a steadfastness that human applause and the fear of man are powerless to shake when sustained by divine power.