A special feature of the book is that the learned Swamiji quotes copiously from various Srutis, Smritis and Puranas as also from different orthodox commentators to explore the real meaning of the Mantras of the Ishopanishad.
All is the Self or Brahman. The saint, the sinner, the lamb, the tiger, even the murderer, as far as they have any reality, can be nothing else, because there is nothing else.
-Swami Vivekananda