Avishaya is the doorway to enlightenment, straight doorway. Nothing in this world can reveal anything else. Only consciousness can know itself by itself and reveal everything else. Consciousness may be shining, but what about me? You ar o, consciousness, you shining. Everything else shines by your light. The openishut, cut open isha says, tame va hantam anu pati, serbam,. tastiab hasa, servamidam vehati - "Everything here is revealed"
"The objects of knowledge, viz., sound, touch, etc., which are perceived in the waking state, are different from each other because of their peculiarities; but the consciousness of these, which is different from them, does not differ because of its homogeneity." Inspired by this verse from the book, Pancadasi by Vidyaranya (Ch 1, Verse 3), Swami Sarvapriyananda gives a discourse on direct path of Advaita Vedanta.