Yoga Vasistha (Sanskrit: योग-वासिष्ठ) is a Hindu spiritual text written by sage Valmiki. It is believed by some Hindus to answer all the questions that arise in the human mind, and can help one to attain Moksha. It recounts a discourse of sage Vasistha to Prince Rama, during a period when the latter is in a dejected state. The contents of Vasistha’s teaching to Rama is associated with Advaita Vedanta, the illusory nature of the manifest world and the principle of non-duality. This is one of the longest texts in Sanskrit after the Mahabharata, and an important text of Yoga. It consists of about 32,000 shlokas, including numerous short stories and anecdotes used to help illustrate its content. In terms of Hindu mythology, the conversation in the Yoga Vasishta takes place chronologically before the Ramayana.
Other names of this text are Mahā-Rāmāyana, ārsha Rāmāyana, Vasiṣṭha Rāmāyana, Yogavasistha-Ramayana and Jnanavasistha.
Excerpt from Wikipedia Article Yoga Vasistha