Introduction to Tripura Rahasyam - త్రిపురా రహస్యము
Tripura Rahasyam means the Mystery beyond the Trinity. The three cities or states of consciousness are waking, dreaming and deep sleep. The underlying consciousness in all of them is called Sri Tripura, the Mother Goddess Tripura Sundari.
The highest truth was first taught by Lord Shiva to Lord Vishnu. Lord Vishnu incarnated on earth as Sri Dattatreya, Lord of the Avadhutas, who taught this to Parasurama, who later taught it to Haritāyana.
The Tripura Rahasya is a dialogue between Lord Dattatreya and Parasurama. It is also called the Haritāyana Samhitā after its author Haritāyana, son of Harita.
It is said to consist of 12,000 slokas in three sections - the Jñāna Khaṇḍa (Section on Supreme Wisdom), the Mahātamya Khaṇḍa (Section on the Greatness of Sri Devi), and the Caryā Khaṇḍa (Section on Conduct). Of these the first consists of 6,687 slokas; the second of 2,163 slokas; and the third is untraceable.