First Book of Kings (Author Compiled by Isaias from records of Samuel, David, Nathan, and Gad.)
Chapter 29
8dixitque David ad Achis quid enim feci et quid invenisti in me servo tuo a die qua fui in conspectu tuo usque in diem hanc ut non veniam et pugnem contra inimicos domini mei regis
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.