1 Samuel 28:2

And David said again to Achish, "Then thou shalt know what thy servant can do." And Achish said to David, "Then I will make thee keeper of my head forever."

1 Samuel 27:10

And Achish said, "Have ye not been a roving this day?" And David answered, "Yes, in the south of Judah, and in the south of the Jezreelites, and in the south of the Kenites."

2 Samuel 16:16-19

And as soon as he was come, Hushai the Archite went unto Absalom and said unto him, "God save the king, God save the king."

Romans 12:9

Let love be without dissimulation. Hate that which is evil, and cleave unto that which is good.

Treasury of Scripture Knowledge

Summary

And David said to Achish, Surely thou shalt know what thy servant can do. And Achish said to David, Therefore will I make thee keeper of mine head for ever.

Bible References

Surely

1 Samuel 27:10
And Achish said, "Have ye not been a roving this day?" And David answered, "Yes, in the south of Judah, and in the south of the Jezreelites, and in the south of the Kenites."
2 Samuel 16:16
And as soon as he was come, Hushai the Archite went unto Absalom and said unto him, "God save the king, God save the king."
Romans 12:9
Let love be without dissimulation. Hate that which is evil, and cleave unto that which is good.