The man wondered why the dervish said this, but the explanation is that the ego always wants feeding, and the more you feed it the more energy it has. What are you feeding it with? You feed it by your inclinations, by getting praise from people or attentions, benefits, help, or love. Whether these come justly or through injustice, rightfully or not, this ego is never satisfied; it keeps on wanting attention. As a result it begins to rule over the higher faculties of inspirational and spiritual power, of wisdom, reason, and justice -- all the beautiful qualities. This Nafs or ego or Satan (for the ego is Satan) governs all these faculties, and a man cannot become saintly until he has crushed it; there is no other way whatever than this. The saintly personality cannot come into being until all this is achieved.