Matsya Purana — Narasimha’s Victory over Hiraṇyakaśipu and the Catalogue of Apocalyptic Omens
मही कालमही चैव तमसा पुष्पवाहिनी जम्बूद्वीपं रत्नवटं सर्वरत्नोपशोभितम् //
mahī kālamahī caiva tamasā puṣpavāhinī jambūdvīpaṃ ratnavaṭaṃ sarvaratnopaśobhitam //
In Jambūdvīpa there are (regions named) Mahī and Kālamahī, as well as Tamasā and Puṣpavāhinī; and there is Ratnavaṭa—adorned with every kind of jewel.
This verse is not about Pralaya; it belongs to cosmographic description, listing named regions/features of Jambūdvīpa and highlighting a jeweled locale (Ratnavaṭa).
Directly it does not prescribe dharma; indirectly, Purāṇic geography frames the king’s ideal as a ruler who knows the world’s sacred layout—places, rivers, and famed regions—supporting pilgrimage, protection of routes, and patronage of holy sites.
No explicit Vāstu rule is stated; however, the motif of a ‘jewel-adorned’ place (Ratnavaṭa) aligns with Purāṇic ideals of auspicious, ornamented sacred spaces—useful for SEO contexts like “Puranic temple aesthetics” rather than technical Matsya Purana Vastu Shastra tips.