Its purpose is to show that Brahman as the eternal subject, Pratyagatman, the inner Self is never an object. It cannot be maintained that Moksha or Brahman is something to be ceremonially purified. There is no room for a purificatory ceremony in the eternally pure Brahman. Brahman is the Self or Atman of all. It can neither be striven nor avoided.
All objects perish because they are mere modifications of the five elements.
But the Soul or Brahman is immortal and unchanging. It is in its essence eternally pure and free. He who identifies himself with his body experiences pain. A sage who has removed Dehadhyasa or identification of the body by identifying himself with the pure, all-pervading Brahman will not experience pain. A rich man who is puffed up by the conceit of his wealth is affected with grief when he loses his wealth.