1 Samuel 28:2
And David said to Achish, Surely you shall know what your servant can do. And Achish said to David, Therefore will I make you keeper of my head for ever.
Torrey's Topical Textbook—AKJV

1 Samuel 29:9
And Achish answered and said to David, I know that you are good in my sight, as an angel of God: notwithstanding the princes of the Philistines have said, He shall not go up with us to the battle.
Torrey's Topical Textbook—AKJV