1 Samuel (Author Compiled by Isaiah from records of Samuel, David, Nathan, and Gad.)
15:20And Saul said to Samuel, I have indeed hearkened to the voice of Jehovah, and have gone the way which Jehovah sent me, and have brought Agag the king of Amalek, and have utterly destroyed the Amalekites.
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.