Navaratri (or Navaratra) simply means nine nights. Timing of festivals is as per lunar tithis and these don’t exactly correspond to solar days. The nine days are from pratipada (first lunar day) to navami (ninth lunar day), though celebrations can also spill over to dashami (tenth lunar day). There is shukla paksha (lunar fortnight when the moon waxes) and krishna paksha (lunar fortnight when the moon wanes). Typically, krishna paksha is for pitris (ancestors/manes).
Devas and devis will not be worshipped in krishna paksha, only during shukla paksha. Since every month will have a shukla paksha from pratipada to purnima (day of full moon), over the year, there are 12 such Navaratri cycles. From the point of view of worshipping Devi, all 12 aren’t equally important. Four are specific to worshipping Devi, Sharada/Ashvina Navaratri, Vasanta/Chaitra Navaratri, Magha Navaratri and Ashada Navaratri. We are in the middle of Sharada/Ashvina Navratri. Most people I know have heard of Vasanta/Chaitra Navaratri, but have never heard of Magha and Ashada Navaratris. That is because worship during Magha and Ashada Navaratri is secret, and these are known as gupta Navaratris.
There is an ancient tradition of Devi worship in India, much before what is perceived as recorded history. Regardless of the part of the country, Navaratri is associated with Devi worship. The form differs. One should mention ‘Devi Suktam’. There are several such Devi Suktams from different texts—(1) ‘Devi Suktam’ (Rig Veda); (2) ‘Shri Suktam’ (Rig Veda); (3) ‘Devi Suktam’ (from tantra texts); (4) ‘Durga Suktam’ (Taittiriya Aranyaka); and (5) ‘Ratri Suktam’ or ‘Devi Stotram’ (from Durga Saptashati). Other than the Rig Veda ones, the others find their origin in a section of the Markandeya Purana known as ‘Devi Mahatmya’ or ‘Chandi’. For Devi worship, the Markandeya Purana is the most important in the Itihasa-Purana corpus.
This does not mean that stories about Shiva and Parvati do not occur elsewhere in the Itihasa-Purana corpus. The Mahabharata mentions both—‘Anushasana Parva’ describes an incident where Uma tells Shiva about dharma of women. Valmiki Ramayana has several references to Shiva and Parvati stories. Other than Markandeya Purana and Devi Bhagavata Purana, one should mention Linga and Skanda Puranas from the Itihasa-Purana corpus. ‘Lalita Sahasranama’, which gives us 1,000 names of Lalita, a manifestation of Devi, is from the Brahmanda Purana.
Devi is worshipped in many forms, such as Nava Durga or nine forms of Durga: Shailaputri, Brahmacharini, Chandraghanta, Kushmanda, Skandamata, Katyayani, Kalaratri, Mahagauri and Siddhidhatri. Especially in tantra, she is worshipped as the ten Mahavidyas: Kali, Tara, Tripurasundari (or Shodashi), Bhuvaneshvari, Tripurabhairavi, Chhinnamasta, Dhumavati, Bagalamukhi, Matangi and Kamala.
There is local worship of Devi—often, temple-specific—at other times of the year. In Panchayatana Puja (worship of five Murtis), it is customary for Devi to be worshipped along with Shiva, Vishnu, Surya and the specific ishta devata. If it is specific to Devi’s worship during Navaratri and stories connected with the asura Mahishasura, Markandeya Purana is the most important.
This tells us the story of King Suratha and the vaishya Samadhi. Reduced to a miserable state, they are advised by Rishi Sumedha to worship Devi. To understand Navaratri worship of Devi, one should add Devi Bhagavata Purana, also known as Devi Bhagavatam. The seventh skandha from this text has the famous ‘Devi Gita’. Since one has mentioned ‘Devi Gita’, one should mention Devi Upanishad. There are also other Puranas like Kalika Purana and Chandi Purana.
In Bengal, Devi worship is equated with Durga worship. Generations have grown up with the belief that Mahalaya signifies the onset of Durga Puja. Historically, Mahalaya has nothing to do with Durga Puja. Mahalaya signifies the beginning of shukla paksha. Today, every Bengali thinks Durga Puja happens on saptami, ashtami and navami. That’s not true either.
This is because of standardisation courtesy community-driven Pujas. Texts speak of seven different kalpas (modes) of worshipping Durga. (1) Starting on krishna paksha navami that precedes Mahalaya in Bhadra and concluding on Ashvina shukla paksha navami, lasting for 15 days; (2) Starting on shukla paksha pratipada and concluding on navami, lasting for nine days; (3) Beginning on shashthi and concluding on navami, lasting for four days; (4) Starting on saptami and ending on navami, for a period of three days; (5) Beginning on ashtami and ending on navami, for a period of two days; (6) Only on ashtami; (7) Only on navami. When non-community-driven Durga Pujas occur, a practice fast dying out, the other six modes are still followed. But because of standardisation, most have been reduced to (4). If you want to read more about these other modes, I recommend the work of Raghunandana Bhattacharya, from the 16th century.
He was known as Smarta Raghunandana and wrote copiously on several topics. For Durga Puja purposes, the relevant texts are Durgotsav Tattva, Durgapuja Tattva and Kritya Tattva. Bhattacharya wasn’t the only one who wrote on Durga worship. For example, before him, there was Acharya Shulapani.
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