Matsya Purana — Manvantaras
इत्येते ऋषयः प्रोक्तास् तपसा ऋषितां गताः तेषां पुत्रानृषीकांस्तु गर्भोत्पन्नान्निबोधत //
ityete ṛṣayaḥ proktās tapasā ṛṣitāṃ gatāḥ teṣāṃ putrānṛṣīkāṃstu garbhotpannānnibodhata //
Thus these sages have been described—through austerity they attained the state of perfected seers. Now learn of their sons, the Ṛṣikās, who were born from the womb (i.e., through embodied generation).
This verse is not describing Pralaya; it shifts to lineage narration, stating that the previously named sages attained seerhood through tapas and introducing their womb-born descendants.
Indirectly, it supports the Purāṇic ideal that disciplined tapas and lawful progeny (garbha-utpanna, born through sanctioned household life) sustain dharmic lineages—knowledge a king preserves through patronage of sages and genealogical memory.
No Vāstu or temple-rule detail appears here; the ritual takeaway is the emphasis on tapas (austerity) as a means to spiritual attainment, before moving into rishi-descendant cataloging.