Matsya Purana — The Observance of Viśoka-Dvādaśī: A Lakṣmī–Viṣṇu Vow for Sorrow-Removal and P...
पुण्यमाश्वयुजे मासि विशोकद्वादशीव्रतम् दशम्यां लघुभुग्विद्वान् आरभेन्नियमेन तु //
puṇyamāśvayuje māsi viśokadvādaśīvratam daśamyāṃ laghubhugvidvān ārabhenniyamena tu //
In the auspicious month of Āśvayuja, the learned person should begin the sacred Viśoka-Dvādaśī vow. On the tenth day (Daśamī), eating lightly, he should undertake it with disciplined observances.
This verse does not discuss Pralaya; it focuses on ritual discipline—how to commence the Viśoka-Dvādaśī vow in the month of Āśvayuja with regulated conduct.
It presents a practical dharma guideline: a disciplined householder (and by extension a king as an exemplar of dharma) should begin the vow from Daśamī, adopting light food and restraint (niyama) as preparation for Dvādaśī observance.
The ritual significance is procedural: the vrata is initiated on Daśamī with light eating and regulated observances, indicating preparatory purification before the Dvādaśī vow.