108. Amir al-mu'minin, peace be upon him, said: In man there is a piece of flesh attached to him with a vein and it is the strangest thing in him. It is the heart. It has a store of wisdom and things contrary to wisdom. If it sees a ray of hope, eagerness humiliates it and when eagerness increases, greed ruins it. If disappointment overtakes it, grief kills it. If anger rises in it, a serious rage develops. If it is blessed with pleasure, it forgets to be cautious. If it becomes fearing, it becomes heedless. If peace extends all round, it becomes neglectful. If it earns wealth, freedom from care puts it in the wrong. If trouble befalls it, impatience makes it humble. If it faces starvation, distress overtakes it. If hunger attacks it, weakness makes it sit down. If its eating increases, heaviness of stomach pains it. Thus, every shortness is harmful to it and every excess is injurious to it.