Matsya Purana — Dynastic Genealogies: Paurava–Anu Lines
ततस्तं दीर्घतमसं सुरभिर्वाक्यमब्रवीत् विचार्य यस्माद्गोधर्मं प्रमाणं ते कृतं विभो //
tatastaṃ dīrghatamasaṃ surabhirvākyamabravīt vicārya yasmādgodharmaṃ pramāṇaṃ te kṛtaṃ vibho //
Then Surabhī spoke these words to Dīrghatamas: “O mighty one, since you have reflected and established the dharma concerning cows as the authoritative standard of right conduct…”
This verse does not discuss pralaya; it frames dharma in ethical terms, stating that “go-dharma” (duties centered on cows and their protection) is treated as a recognized standard of righteousness.
By presenting go-dharma as a pramāṇa (authoritative benchmark), it implies that rulers and householders should uphold cow-protection, proper care, and related charitable/ritual duties as a key measure of moral governance and daily conduct.
No direct Vāstu or temple-building rule appears here; the ritual takeaway is that dharma connected with cows is treated as a normative yardstick—often linked in Purāṇic practice to gifting cows, maintaining cowsheds, and supporting sacrificial/household rites.