Ashtavakra Samhita

Ashtavakra was a Vedic seer and composer of the Ashtavakra Gita. ... subsequently made more popular by the effort and writings of Adi Shankaracharya. Ashtavakra Gita is a dialogue between Ashtavakra and Janaka on the nature of soul, reality, and bondage. It offers a radical version of non-dualistic philosophy. The Gita insists on the complete unreality of the external world and absolute oneness of existence.