Matsya Purana — The Rite of the Jaggery-Cow
तस्मादग्रे हरेर्नित्यम् अनन्तं गीतवादनम् कर्तव्यं भूतिकामेन भक्त्या तु परया नृप //
tasmādagre harernityam anantaṃ gītavādanam kartavyaṃ bhūtikāmena bhaktyā tu parayā nṛpa //
Therefore, O king, one who seeks prosperity should always, in the presence of Hari, perform unceasing sacred song and instrumental music, doing so with supreme devotion.
This verse does not describe pralaya directly; it emphasizes a practical bhakti-discipline—continuous devotional music before Hari—as a means to welfare and stability even amid cosmic uncertainty.
It frames devotion as a duty-linked practice: a ruler (and likewise a householder) seeking prosperity and public well-being should maintain regular worship of Vishnu through song and instruments, cultivating “parā-bhakti” rather than mere formality.
Ritually, it points to upacāra in pūjā: gīta (hymns) and vādya (instruments) offered before the deity. Architecturally it implies a worship setting (temple or shrine) where such offerings are performed, aligning with Matsya Purana’s broader temple-ritual culture rather than giving a specific Vāstu rule in this verse.