There exists a legend in the world of Islam, and some believe that it really did occur -- some say once, and some say it happened more than once -- that the angels from heaven descended on earth and cut open the breast of the Prophet; they took away something that was to be removed from there, and then the breast was made as before. According to the Sufi point of view this is a symbolical legend. It explains what is necessary in the life of man, to allow the plant of divine love to grow in his heart. It is to remove that element which gives the bitter feeling.