In a letter to Malik Ashtar (RA), Imam Ali (AS) wrote: Never get too complacent! To rely on your good deeds, and like to be praised; as these are the best moments for Satan to attack you, and destroy all the good deeds. Never think people are under your obligation because of the services you have provided for them, or consider big/great what you have done for them, or promise people and then break it. Never ask for any privilege for whatever you are equal with other people! Do not neglect those affairs/cases which are obvious to everyone, because any how you are responsible to people for them, and soon the veils/curtains will be removed and you will be avenged for what happened to oppressed ones [1].
[1] Nahjul Balaghah, Letter 53.
