1 Samuel 29:8

And David said unto Achish, But what have I done? and what hast thou found in thy servant so long as I have been with thee unto this day, that I may not go fight against the enemies of my lord the king?

Cross-references

In 1 Samuel 12:3, Samuel asks 'what have I done?' defending his integrity — David uses the same phrase to protest his loyalty.

In 1 Samuel 17:29, David asks 'what have I done?' to Eliab — same self-defense when his motives are questioned.

In 1 Samuel 20:8, David asks Jonathan if there is any iniquity in him — same appeal to innocence when loyalty is doubted.

In 1 Samuel 26:18, David asks Saul 'what have I done?' — identical protest of innocence against accusations.