1 Chronicles (Author Compiled by Isaiah and Ezra from records of Nathan, Gad, Iddo, Ahijah, Jehu and others.)
Chapter 17
7Now therefore thus shalt thou say unto my servant David, Thus saith the LORD of hosts, I took thee from the sheepcote, even from following the sheep, that thou shouldest be ruler over my people Israel:
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.