Matsya Purana — Vrata-Ṣaṣṭhī: The Sixty Sacred Vows
यश्चोपवासी सप्तम्यां समान्ते हैमपङ्कजम् गाश्च वै शक्तितो दद्याद् धेमान्नघटसंयुताः एतत् सौरव्रतं नाम सूर्यलोकफलप्रदम् //
yaścopavāsī saptamyāṃ samānte haimapaṅkajam gāśca vai śaktito dadyād dhemānnaghaṭasaṃyutāḥ etat sauravrataṃ nāma sūryalokaphalapradam //
Whoever fasts on the seventh lunar day and, at the conclusion of the observance, offers a golden lotus and also, according to one’s capacity, donates cows together with pots filled with food—this is called the Sauravrata, and it bestows the fruit of attaining the world of the Sun (Sūryaloka).
This verse does not discuss pralaya; it teaches a ritual vow (Sauravrata) focused on fasting, charitable gifts, and the merit-fruit of reaching Sūryaloka.
It frames dharma as disciplined observance (upavāsa) and socially sustaining generosity (dāna of cows and food), duties especially emphasized for householders and rulers who can support others according to capacity (śaktitaḥ).
The significance is ritual rather than architectural: Saptamī fasting, concluding offerings of a golden lotus, and prescribed donations (cows and food-filled pots) define the Sauravrata’s procedure and its stated result (Sūryaloka).