I read Amos 7:
“Amos answered Amaziah, “I was neither a prophet nor a prophet’s son, but I was a shepherd, and I also took care of sycamore-fig trees. But the Lord took me from tending the flock and said to me, ‘Go, prophesy to my people Israel.’”
-Amos 7:14-15 (NIV)
(3 minutes & 14 seconds of archived audio)