Matsya Purana — Paurava Genealogy
न स्थास्यतीह दुर्बुद्धे तवैतद्वचनं भुवि यावत्स्थास्यसि त्वं लोके तावदेव प्रपत्स्यति //
na sthāsyatīha durbuddhe tavaitadvacanaṃ bhuvi yāvatsthāsyasi tvaṃ loke tāvadeva prapatsyati //
O evil-minded one, this statement of yours will not endure on earth; it will hold only so long as you yourself remain in the world—and then it will collapse.
It does not describe cosmic Pralaya directly; it uses the idea of collapse (prapatsyati) to stress the impermanence of a wicked person’s claim—its ‘end’ arrives with the doer’s downfall.
It warns that bad advice and deceitful speech are unstable foundations for rule or household life; a king should test counsel and character, and a householder should avoid harmful, manipulative words that inevitably ruin trust.
No Vastu or ritual procedure is stated; the takeaway is ethical—speech and intention must be sound, because unstable (adharmic) foundations ‘collapse,’ a principle often applied metaphorically even when discussing stable construction or proper rites elsewhere in the Matsya Purana.