Katha Rudra Upanishad is a minor Upanishad. Lord Brahma teachings about Atman in this text. The text deals with spontaneous flash of illumination (realization of nature of the Atman as a result of the pure knowledge arising out of the power of Brahmacharya) that irradiates the world is ever shining. It is indeed the witness of the world, the universal Self, embodiment of purity, substratum of all beings, of the very nature of absolute consciousness through and through. That Brahman which is the object of real or supreme Knowledge, is Truth, awareness, Joy (Bliss) and non-dual (One without a second). He who realizes the inner Self as ‘I am Brahman’, he becomes Brahman Itself.