This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The Devi Mahatmya, seven hundred verses recounting the goddess Durga's defeat of the buffalo demon Mahishasura, is one of the most widely recited texts in living Hindu devotional practice, chanted in full during Durga Puja and Navaratri across the subcontinent. Most people who hear or chant it, though, encounter it as its own self-standing work, the Durga Saptashati or Chandi, with little sense that it sits embedded inside a much older and much less famous frame: the Markandeya Purana.
That frame is worth returning to, because it explains a structural habit of the whole Purana genre rather than being incidental to this one text. The Markandeya Purana as a whole is built as an extended answer session, the sage Markandeya responding to questions the sage Jaimini raises about loose threads left in the Mahabharata. Into that question-and-answer frame, later hands inserted an entirely separate hymn cycle celebrating the goddess, one that scholars judge stylistically distinct enough from the surrounding material to have had an independent life before it was folded in.
Puranic texts absorb material this way repeatedly: a frame narrative provides a stable vessel, and later compilers add whatever devotional or narrative material their own moment considered urgent enough to preserve inside it. The Devi Mahatmya is simply the most successful case, a later insertion that eventually outgrew the very text that carried it into wide circulation, still recited today by people who may never open the Purana that first gave it a home.