Numbers 22:33
And the ass saw me, and turned from me these three times: unless she had turned from me, surely now also I had slain thee, and saved her alive. And the ass saw me, and turned from me these three times: unless she had turned from me, surely now also I had slain thee, and saved her alive.
The angel stood in Balaam's way to kill him for his presumptuous folly and perverse course in acting against the Lord's will and express prohibition by going to Balak and the Moabites, the enemies of Israel, out of covetousness and selfishness and love of honor, gain, favor, promotion and rewards, while double-mindedly professing to be God's prophet and loving the wages of unrighteousness, blinded by passion. The donkey saw the angel and God's intervention when Balaam could not, and turned aside from him these three times, thereby preserving Balaam's life and her own, for unless she had turned Balaam would have been slain and she would have been kept alive. Her repeated turns both spared her from being killed and kept Balaam from being killed. Balaam was beside himself with rage, blinded by passion, and cruel toward the animal, beating her and failing to notice anything remarkable even in her speaking.
When the angel revealed himself, Balaam was terrified, left his beast, bowed in humility before him, and heard his way declared perverse before God, told that he came out to withstand him because his way was perverse. The angel then impressively warned Balaam against gratifying the Moabites by cursing Israel and gave him permission to pursue his journey. This was so that God could glorify His name before Israel's enemies by showing that a covetous man like Balaam dared not pronounce a curse against Israel for any promises of promotion or rewards, which was important because Israel had to overcome the Moabites in order to overcome the inhabitants of Canaan. God used the blocking angel to turn Balaam aside from his purpose and keep him alive, just as He used unseen angels to stop Saul's messengers from harming David.
The verse belongs to the account in which Balak conducts Balaam from one point to another in the vain hope that he might be induced to change Israel's blessing into a curse. That repeated effort illustrates repeated efforts to move a faithful witness from steadfastness, which human applause and fear of man are alike powerless to shake when he stands firm as a rock and sustained by divine power, as in Luther's refusal of compromise.