Matsya Purana — Solar–Lunar Motions
चलितं ते पुनर्धर्मं स्थापयन्ति युगे युगे संतप्ततपसा चैव मर्यादाभिः श्रुतेन च //
calitaṃ te punardharmaṃ sthāpayanti yuge yuge saṃtaptatapasā caiva maryādābhiḥ śrutena ca //
Whenever dharma becomes unsettled, they re-establish it again and again in every age—by rigorous austerity, by the boundaries of right conduct, and by the authority of Śruti (revealed scripture).
It does not describe pralaya directly; it teaches a recurring pattern across yugas: when dharma declines, it is restored through tapas, moral boundaries (maryādā), and Vedic revelation (śruti).
It implies that rulers and householders should stabilize society by supporting śruti-based norms, enforcing maryādā (lawful limits and ethical discipline), and honoring tapas—i.e., self-restraint and religious observance—as instruments for restoring dharma when it wavers.
No specific Vāstu or iconographic rule appears here; the ritual takeaway is that śruti-authority and disciplined practice (tapas, maryādā) are presented as the legitimizing foundations for correct rites and social-religious order.