For prophecy never had its origin in the human will, but prophets, though human, spoke from God as they were carried along by the Holy Spirit. (NIV)

For no prophecy ever originated because some man willed it [to do so--it never came by human impulse], but men spoke from God who were borne along (moved and impelled) by the Holy Spirit. (AMP)

For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost. (KJV)