1 Samuel 25:21

Now, David had said, Surely in vain have I kept all that this fellow hath in the wilderness, in protecting his wealth in flocks, so that nothing was missed of all that pertained unto him; and he hath requited me evil for good. David had been bitterly disappointed in his expectation of receiving any recognition whatever on the part of Nabal and had now flared up in passionate anger, which was not right.