1 Samuel 28:1-2
1 Samuel 28:1-2 ESV
In those days the Philistines gathered their forces for war, to fight against Israel. And Achish said to David, “Understand that you and your men are to go out with me in the army.” David said to Achish, “Very well, you shall know what your servant can do.” And Achish said to David, “Very well, I will make you my bodyguard for life.”