Matsya Purana — The Sun-Vow
या च भर्तृगुरुदेवतत्परा वेदमूर्तिदिननक्तमाचरेत् सापि लोकममरेशवन्दिता याति नारद रवेर्न संशयः //
yā ca bhartṛgurudevatatparā vedamūrtidinanaktamācaret sāpi lokamamareśavanditā yāti nārada raverna saṃśayaḥ //
That woman who is devoted to her husband, her teacher, and her chosen deity—who serves the Veda embodied, by day and by night—she too, O Nārada, attains the world of Ravi (the Sun), honored even by the lords of the gods; of this there is no doubt.
This verse does not discuss Pralaya; it teaches dharma and the spiritual result of steadfast devotion and service, culminating in attainment of Sūrya-loka.
It frames ideal householder conduct as continuous (day-and-night) service aligned with Vedic dharma—expressed through devotion to husband, guru, and deity—indicating that disciplined, relational duty is itself a path to exalted realms.
No Vāstu or temple-construction rule is stated; the ritual takeaway is the emphasis on regular, unwavering daily practice (dina-naktam ācaret) as the core of merit.