Matsya Purana — Yayāti’s Fall
यद्वै नृशंसं तदपत् ह्यमाहुर् यः सेवते धर्ममनर्थबुद्धिः असावनीशः स तथैव राजंस् तदार्जवं स समाधिस्तदार्यम् //
yadvai nṛśaṃsaṃ tadapat hyamāhur yaḥ sevate dharmamanarthabuddhiḥ asāvanīśaḥ sa tathaiva rājaṃs tadārjavaṃ sa samādhistadāryam //
Indeed, they declare that what is cruel is itself a “fall” (downfall). He who practices dharma with a mind fixed on selfish gain is not master of himself; and so too, O King. True dharma is straightforwardness; that is inner collectedness (samādhi); that is the conduct of the noble (ārya).
This verse does not discuss pralaya directly; it teaches ethical causality—cruelty and self-serving ‘dharma’ lead to personal and political downfall, a moral “collapse” rather than cosmic dissolution.
It warns a ruler (and any dharma-follower) that righteousness pursued for gain is not true dharma; the king’s duty is self-mastery, honest straightforward conduct (ārjava), and steadiness of mind (samādhi) as the basis of just governance.
No explicit Vāstu or ritual procedure is stated; the takeaway is foundational: purity of intention and inner discipline are prerequisites for any dharmic act, including ritual performance and patronage of temples.