Tripur Rahasya is a holy book on A-Dwait philosophy written by Haritaayan. It is sometimes called Haritaayan Sanhitaa also because he wrote this. It is said that once Maarkandeya Rishi asked Brahmaa Jee to tell him the secret truth. Brahmaa Jee told him that it will be brought to him in the form of a holy book. When Naarad Jee heard this he came to Earth.

In the meantime Haritaayan was worshipping in Meenaakshee Temple of Madurai (Tamil Naadu, in Southern India). Naarad Jee came to him and told him that he had come to see him as what he was doing to present the secret truth to the world. He said that he found himself unable to do so, so Naarad Jee meditated on Brahmaa Jee and Brahmaa Jee immediately appeared there before them and endowed Haritaayan to write four chapters of the book a day. Later Brahmaa Jee and Naarad Jee were the first people to read that book after it had been written.

It consists of 12,000 Shlok distributed in three sections - (1) The Mahaatmya Khand, a section on Greatness of Shree Devee, 6,687 Shlok; (2) Gyaan Khand, a Khand on Supreme Wisdom, 2,163 Shlok; and (3) Charyaa Khand, a section on Conduct. The first two Khand are available but the third one is not traceable. The first section includes prelude to the work and writes about Durgaa, Kaalee, Lakshmee, Saraswatee, Lalitaa, Kumaaree etc Devee and their exploits found in Brahmaand Puraan, Maarkandeya Puraan and Lakshmee Tantra. It mostly covers Durgaa Sapt Shatee and Lalitaa Upaakhyaan.

Tripur Rahasya starts with "Om Namah" and ends with "Shree Tripuraiv Hreem". Om is the well-known symbol of signifying the Supreme Being and Hreem is the symbol of the same as the Supreme Goddess. Thus the whole book is enclosed between these two symbols.

There is a Sanskrit Sanhitaa on Tripur Rahasya, named "Taatparya Deepikaa", written in 4932 of Kali era (ie 1831 AD) by one Dravid Srinivas, son of Vyadianath Deekshit of the village of Mahaa Pushkar in South India.

From Tripur Rahasya Translation in PDF
Shree Tripur Rahasya is an ancient work in Sanskrit which has been printed all over India. The latest and best edition was brought out in the Kashi Sanskrit Series in 1925. The book is said to have been printed once before and issued in loose leaves. There was also an edition in book form printed in Belgaam towards the end of last century - 20th century. (The original Sanskrit text unfortunately appears to have been out of print for some years.)

Origin of Tripur Rahasya
The esteem in which the work is held for its sanctity may be gauged from an account of it given in the Preface to the Maahaatmya Khand. Mahaadev Jee originally taught the Highest Truth to Vishnu who in turn taught it to Brahma Jee in the Celestial regions. Later Vishnu incarnated on Earth as Shree Dattaatreya, the Lord of the Avadhoot (the naked sages), and taught it to Parashuraam Jee with the added injunction that it should be communicated to Haritaayan who would later seek the Truth from him. Parashuraam Jee thus realized the Self by the guidance of Shree Dattaatreya Jee and dwelt on the Malaya Hill in Southern India.

In the meantime, a Braahman, by name Sumant, living on the banks of the Saraswatee River had a son, Alark by name, who used to hear his mother called "Aayee Aayee" by his father. Being a child, he too addressed his mother "Aayee". He died in his childhood, and his last words on his death-bed were "Aayeei Aayee" only. This sound is however sacred to the Goddess. Having been uttered in all innocence and purity of mind, it conferred unexpected merit on the dying child. He was later born as Sumedh, a son to Harit. He was named as Haritaayan on his father's name. His spirituality developed as he grew up and he sought Parashuraam Jee to learn the highest good from him, who in turn imparted to him the knowledge which he had gained from Dattaatreya. Parashuraam Jee told him also that his master had predicted the compilation of the knowledge of the Highest Truth by Haritaayan for the benefit of mankind.

Once Haritaayan was worshipping Shree Meenaakshee Devee in the temple at Madurai in Tamil Naadu, that Naarad Jee appeared to him and said that he had come from Brahm Lok in order to see what Haritaayan was going to present to the world in the form of an Itihaas (history) containing the Supreme Spiritual Truth. Haritaayan was bewildered to see him and asked him what the Saint expected of him. Naarad Jee said: "There was an assembly of saints in Brahm Lok. Maarkandeya Jee asked Brahmaa Jee about the Sacred Truth. Brahmaa Jee said that it would be brought out by you in the form of a holy book. So I have come to ask you about it."

Haritaayan was at a loss and pleaded inability to reproduce the Sacred Truth learned from Parashuraam Jee. Naarad Jee then meditated on Brahmaa Jee who appeared before them and asked what the matter was. When Naarad put the whole matter before him, he turned to Haritaayan and blessed him, endowing him with the ability to produce the book at the rate of four chapters a day. He also referred to Haritaayan's past and attributed his present inability to remember what he learnt to the casual and undisciplined utterance of the sacred syllable in his past incarnation. Brahmaa Jee further enjoined Naarad Jee to be the first one to read Haritaayan's work when it was completed.

Structure of Tripur Rahasya
The work was thus written by Haritaayan and is also called after his name Haritaayan Samhitaa. It is said to consist of 12,000 Shlok in three sections -
(1) The Maahaatmya Khand - Consists of 6,687 Shlok. Section on the Greatness of Shree Devee contains the prelude to the work and later treats mostly of the manifestations of the Supreme Being as Durgaa, Kaalee, Lakshmee. Saraswatee, Lalitaa, Kumaaree, etc. and their exploits and found in Brahmaand Puraan, Maarkandeya Puraan and Lakshmee Tantra. Its contents mostly cover the ground of Durgaa Sapt Shatee and of Lalitaa Upaakhyaan. Shree Vidyaa (worship of the Supreme Being as Goddess) has a very holy tradition traced to the Ved. There are two principal divisions, known as -- and --former was practiced by Indra, Chandra, Manu, Kuber, etc. It is the simpler of the two and also more common. The other was practiced by Lopaamudraa and is approved of the wise. The origin, Mantra and Yantra of the goddess Tripuraa, also known as Lalitaa or Lalitaa Tripur Sundaree are also given here.

(2) Gyaan Khand (Section on Supreme Wisdom) - Consists of 2,163 Shlok. The Gyaan Khand or section on knowledge elaborates on the themes of consciousness, manifestation, and liberation.

(3) Charyaa Khand (Section on Conduct) - is not available. 

Shree Tripur Rahasya, otherwise Haritaayan Sanhitaa, begins with "Salutations to Aum" and ends with "Tripur is only Hreem". Aum is well known as the sacred syllable signifying the Highest Being in the abstract; so also "Hreem" is the sacred symbol of the same as the Goddess. The contents of the book are thus enclosed by these two symbols - the most sacred in the Ved and the work is equally sanctified.

In Sootra Bhaashya (the commentary on Brahm Sootra). Shree Shankar has used the story of Samvart as found in Tripur Rahasya, in his commentary on "Brahm" (Sootra), with approval.

The Tripur Rahasya is believed to be an abbreviated version of the original Datta Sanhitaa or Dakshinaamoorti Sanhitaa traditionally ascribed to Dattaatreya. This more lengthy work was summarized by Dattaatreya's disciple Paramaasur, whose disciple, Sumedh Haritaayan, scribed the text. Thus, this text is sometimes referred to as the Haritaayan Sanhitaa. In the Taantrik tradition, the Tripuropasti Paddhati is supposed to have been written by Shree Dattaatreya Jee. This is mentioned in Tripur Rahasya. The summary of Tantra in the Parashuraam Kalp Sootram is also supposed to have been written by Shree Dattaatreya Jee.

Thus Tripur Rahasya is the dialog between Dattaatreya Jee and Parshuraam Jee told by Haritaayan.