First Book of Kings (Author Compiled by Isaias from records of Samuel, David, Nathan, and Gad.)
Chapter 21
2et ait David ad Ahimelech sacerdotem rex praecepit mihi sermonem et dixit nemo sciat rem propter quam a me missus es et cuiusmodi tibi praecepta dederim nam et pueris condixi in illum et illum locum
Original from The Bible Foundation - bf.org. They claim public domain status for their original text.