Imam al-Kazim (as): Do not regard a great deal of good that you do as too much and do not deem your petty sins as insignificant, for verily petty sins accumulate until they become a great deal. Have fear of Allah in private so you can maintain fairness despite yourselves, hasten towards obedience to your Lord, be truthful in your speech, return the trust [to its owner], for verily that is for your own good, and do not engage in that which is not lawful, for it is in your own detriment. al-Kāfī