Numbers 22: 26-28
Then the
angel of the LORD moved on ahead and stood in a narrow place where there
was no room to turn, either to the right or to the left.
When the donkey saw the angel of the LORD, it lay down under Balaam, and he was angry and beat it with his staff.
Then
the LORD opened the donkey's mouth, and it said to Balaam, "What have I
done to you to make you beat me these three times?"