Matsya Purana — Tārakāsura’s Austerity and Boon; Mobilization for War; Bṛhaspati’s Fourfold P...
मन्यन्ते दुर्जना नित्यं साम चापि भयोदयात् तस्माद् दुर्जनम् आक्रान्तुं श्रेयान्पौरुषसंश्रयः //
manyante durjanā nityaṃ sāma cāpi bhayodayāt tasmād durjanam ākrāntuṃ śreyānpauruṣasaṃśrayaḥ //
Wicked men always construe even conciliation as born of fear; therefore, when confronting the wicked, it is better to rely on firmness and manly resolve—the strength of decisive action.
This verse does not address pralaya; it is a practical nīti teaching about human behavior—specifically how the wicked misread gentleness as fear.
For a king (and, by extension, a householder managing conflicts), it advises discernment: conciliatory speech (sāma) may work with the virtuous, but with the wicked it is often taken as weakness—so one should act with firm resolve to restrain wrongdoing.
No vāstu or ritual procedure is mentioned; the takeaway is ethical and administrative—choose firmness over appeasement when dealing with persistently harmful persons.