1 Samuel 25:21
Now David had said, Surely in vain have I kept all that this fellow hath in the wilderness, so that nothing was missed of all that pertained unto him: and he hath requited me evil for good. Now David had said, Surely in vain have I kept all that this fellow hath in the wilderness, so that nothing was missed of all that pertained unto him: and he hath requited me evil for good.
The verse belongs to the period when David was a fugitive hunted by Saul, after Abiathar son of Ahimelech escaped Saul's slaughter of the priests and fled to David for safeguard. By it David meant that he had guarded all that belonged to Nabal in the wilderness, including his possessions and household, so that nothing was lost. That good was repaid with evil when Nabal denied David's request for food and answered with insult.
In anger and indignation at the injustice, David treated the wrong as a personal injury he had a right to punish and determined to take revenge by attacking. His decision to attack was impulsive and unlike the character he was learning to develop, showing he still needed to learn patience through hardship. The verse belongs to the account of David's response to Nabal's insult and Abigail's intervention, in which Abigail acted promptly and on her own to keep David from revenge, showing that a woman may act decisively when she knows the course is right before God.