David said to Achish, Therefore you shall know what your servant will do. Achish said to David, Therefore will I make you keeper of my head for ever.
therefore will I make thee keeper of mine head for ever; the captain of his bodyguard, which post he should hold for life; or he proposed to put him into this post, that he might be with him, near his person, and under his eye, that he might observe how he behaved himself; which may show some suspicion of him.