shrImahAtripurasundarI chandramouleshwarebhyo namaH
People recite selections from Puranas like Harivamsha, Devi Bhagavata, Vishnu Bhagavata, Garuda Purana etc. However, these are not recited as a Mala mantra like Saptashati. Saptashati belongs to a totally different genre. Kavacha, Kilaka etc. chanted traditionally are also not a part of Markandeya Purana. The Krama followed, wherein Saptashati is not merely a Puranic passage, but a Mala mantra, is essentially Tantric, derived from Rudrayamala, Skandayamala, Damara Tantra, Varahi Tantra, Katyayani Tantra etc. So, one can chant Saptashati without Kavachadi Traya, Nyasas or the Navarna Japa, but only as a Puranic Stuti and not as a Siddha Mala mantra. The Pramana is in Katyayani Tantra which says: Saptashati chanted without Navarna Japa is like trying to eat a mango seed and hoping to grow a mango tree and consume the resulting mango fruit. Ample warning about Yogini Shapa is also mentioned. Even otherwise, people have not understood Saptashati. If one observes Bhashyas like Guptavati, the first three Shlokas of Saptashati give out in code, the Navarna Mantra. Navarna Mantra may be seen in lots of places in Saptashati. Only with Navarna Japa, Saptashati is a mantra or else it is a Stotra. One should go by Shastra Pramanas, then the Sampradaya and words of the elders and the enlightened like Bhaskaracharya, Haradutta etc, and should not conclude based on the practices of people. Shastras clearly state that a person should NEVER attempt to do Saptashati Japa (as a Mala Mantra) without Navarna Diksha. There are ample instances of adverse effects observed if this rule is not followed. Nine lakhs of Japa is prescribed as a pre-requisite to chant Saptashati. Actually the elevation from Stotra to Stotramaka Mala mantra happens due to the energy of the associated Moola mantra. It is the Moola mantra that opens the power of the Stotra to the Sadhaka and makes it a mantra for him. Without the Moola mantra, the Sadhaka only gets an iota of the limitless energy of these Stotras. The key to open these boxes is necessarily the Moola mantra. Also, Saptashati requires Shapoddhara and Utkilana mantras, which again are `mantras' only if received from the Guru. Moreover, Ratri Sukta and Devi Sukta should be chanted with a proper understanding of the Swaras.
Saptashati and Navarna are related in two ways. While during Purashcharana of Saptashati (Mala mantra), chanting Navarna as a necessary Anga of Saptashati (Damara, Skandayamala) is the first aspect. The other is the recitation of Saptashati as a part of Navarna Purashcharana (Durga Kalpadruma, Rudrayamala, Katyayani, Varahi Tantras). In the first case, Navarna is an absolute Anga of Saptashati. In the second case, the primary importance is of Navarna. Thus considering the angangi nyAya, Navarna is an absolute necessity in either cases, and the only way to do it is to obtain it from a Guru. One needs to firmly believe the fact that the Guru arrives when one is ready for it. One need not have to go in search of one, or try to please Sridevi only by chanting Lalita Sahasranama, Saptashati or Kavachas, which require certain Adhikaras on the part of the Sadhaka. Other Stotras / Sahasranamas etc., which are not guarded by these restrictions, should be recited to obtain divine grace.
A Durga temple was opened in some place in Andhra Desha and the temple committee appointed a priest. After few months, the priest went with Prasadam to H H Sri Chandrashekhara Bharati Mahasannidhanam and said, "Your Holiness, I have recited Saptashati 108 times and brought you Prasadam. Please accept it and bless me". Mahaswamigal gazed at him for a second and said, "How is your daughter?" The startled Brahmana answered, "She is unwell these days. She is suffering from epileptic fits". Mahaswamigal immediately said, "Without Navakashari you have been chanting Saptashati. This is like banging your head on an iron box to open it. You have been sent here by Sharadambal only because of your past Samskaras and Bhakti. Please receive the mantra as per the proper means from Sri Srikantha Sastrigal, perform Laksha Japa and then start chanting Saptashati. Without a Guru, don't try experimenting with Mani, Mantra and Aushadha. Adi Acharya has gracefully given us divine Stotras with miraculous powers. The uninitiated should chant these Stotras with faith and obtain blessings of the divine. The importance of pronunciation need not be reiterated here as the story of bhAryAM bhakShatu bhairavi is well known to most. As I listed earlier, there are purva and uttarangas for Navarna Mahavidya and these need to be learnt from Sadguru along with the meaning of the Navarna Mahamantra discussed in Devyatharvashirsha. Guru is the final authority and the instructions of a Sadguru, who is a Sampradayavit and enlightened, never contradict the Shastras.