Numbers 22:20-23

²⁰And God came to Balaam at night, and said to him, If the men come to call thee, rise and go with them; but yet the word which I shall say to thee, that shalt thou perform.

²¹And Balaam rose in the morning, and saddled his ass, and went with the princes of Moab.

²²And God's anger was kindled because he went: and the angel of the LORD stood in the way for an adversary against him. Now he was riding upon his ass, and his two servants were with him.

²³And the ass saw the angel of the LORD standing in the way, and his sword drawn in his hand: and the ass turned aside out of the way, and went into the field: and Balaam smote the ass, to turn her into the way.