Matsya Purana — Catalogue of the Eighteen Puranas
मीमांसां धर्मशास्त्रं च परिगृह्य मया कृतम् मत्स्यरूपेण च पुनः कल्पादावुदकार्णवे //
mīmāṃsāṃ dharmaśāstraṃ ca parigṛhya mayā kṛtam matsyarūpeṇa ca punaḥ kalpādāvudakārṇave //
Having taken up and safeguarded the Mīmāṃsā and the Dharmaśāstra that were established by me, I again—assuming the form of Matsya—preserved them in the primeval ocean at the beginning of the kalpa.
It implies that at the kalpa’s turning point—amid the primeval flood-waters—sacred systems of dharma and Vedic interpretation are preserved by the divine (as Matsya) so they can re-emerge in the next cycle.
By foregrounding Dharmaśāstra and Mīmāṃsā, it points rulers and householders to stable sources of right conduct: law/duty (dharma) and correct understanding of Vedic injunctions—standards meant to endure even when the world undergoes dissolution.
The ritual significance is primary: Mīmāṃsā denotes the discipline of interpreting and applying Vedic rites correctly, indicating that proper ritual order is safeguarded across pralaya; no direct Vāstu or temple-building rule is stated in this verse.