Dhakshinamoorthy Upanishad
It is attached to the Krishna Yajurveda and classified as one of the 14 Shaiva Upanishads. The text is notable for asserting that Dakshinamurti is an aspect of Shiva, an aid to the liberating knowledge that Shiva is within oneself as Atman (self, soul), and everything one does in daily life is an offering to this Shiva. The text is named after Jnana (knowledge) aspect of the Hindu god Shiva, as Dakshinamurti which means giver of knowledge. He is traditionally the expounder of the Shastras, represented as seating under a Banyan tree in the Himalayas resplendent with energy and bliss, surrounded and revered by sages, in a yoga pose (virasana), holding the fire of knowledge in one hand and a book or snake or lotus or nilotpala flower in another. Dakshinamurti is the "teacher-god", with Atma-vidya, literally the knowledge of Atman (soul, self). He is the ancient guru, who teaches One Self through silence.