It might seem hard work to empty one's heart of all bad impressions and ill feelings, of all bitterness and evil thoughts, and yet it is not nearly so hard as the task of earning one's daily bread. The work in one's everyday life takes most part of the day, the emptying the heart of undesirable things takes but a few moments silence. It is the desire of erasing from the heart every undesirable impression that enables one in time to purify one's heart.