1 Samuel 10:12

And one answered and said, But who is their father? This wonder was presently satisfied by a prudent person among them asking, Who is the father of all those prophets among whom Saul was now one? Who is it that instructs and inspires them but God? They have not this gift from their parents, nor from their education, but by inspiration from God, who, when he pleases, can bestow it on Saul or any other man, and thereby make him a prophet without the help of any other master; as he did Amos, who was no prophet, nor prophet's son, but a herdsman, and a gatherer of sycamore fruit. And therefore wonder not at this matter, but give God the glory. Hence it became a proverb Used when any strange or unexpected thing happened.