Matsya Purana — The Greatness and Procedure of the Aṅgāra
रूपसौभाग्यसम्पन्नः पुनर्जन्मनि जन्मनि विष्णौ वाथ शिवे भक्तः सप्तद्वीपाधिपो भवेत् //
rūpasaubhāgyasampannaḥ punarjanmani janmani viṣṇau vātha śive bhaktaḥ saptadvīpādhipo bhavet //
Endowed with beauty and auspicious fortune, from birth to birth one becomes a devotee of either Viṣṇu or Śiva, and may even become the sovereign lord of the seven continents (saptadvīpas).
It does not directly describe pralaya; it emphasizes karmic and devotional results across repeated rebirths, implying continuity of saṃsāra rather than a flood/dissolution narrative.
It frames devotion (bhakti) as a source of auspiciousness, prosperity, and even sovereignty; for householders and kings, it supports the Purāṇic ethic that righteous devotion undergirds personal fortune and legitimate rule.
No explicit Vāstu/temple-building rule appears here; the ritual takeaway is the promised fruit of steadfast devotion to Viṣṇu or Śiva, often presented as a phala-śruti to motivate worship and observance.