1 Samuel 28:1-2

New Revised Standard Version, Anglicised

28 In those days the Philistines gathered their forces for war, to fight against Israel. Achish said to David, ‘You know, of course, that you and your men are to go out with me in the army.’ ² David said to Achish, ‘Very well, then you shall know what your servant can do.’ Achish said to David, ‘Very well, I will make you my bodyguard for life.’