1 Samuel 10:6-11

and the Spirit of Jehovah will come mightily upon thee, and thou shalt prophesy with them, and shalt be turned into another man. And let it be, when these signs are come unto thee, that thou do as occasion shall serve thee; for God is with thee. And thou shalt go down before me to Gilgal; and, behold, I will come down unto thee, to offer burnt-offerings, and to sacrifice sacrifices of peace-offerings: seven days shalt thou tarry, till I come unto thee, and show thee what thou shalt do. And it was so, that, when he had turned his back to go from Samuel, God gave him another heart: and all those signs came to pass that day. And when they came thither to the hill, behold, a band of prophets met him; and the Spirit of God came mightily upon him, and he prophesied among them. And it came to pass, when all that knew him beforetime saw that, behold, he prophesied with the prophets, then the people said one to another, What is this that is come unto the son of Kish? Is Saul also among the prophets?