First Book of Kings (Author Compiled by Isaias from records of Samuel, David, Nathan, and Gad.)
15:11paenitet me quod constituerim Saul regem quia dereliquit me et verba mea opere non implevit contristatusque est Samuhel et clamavit ad Dominum tota nocte
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.