Matsya Purana — Manvantaras
परत्वेन ऋषन्ते वै भूतादीनृषिकास्ततः ऋषिकाणां सुता ये तु विज्ञेया ऋषिपुत्रकाः //
paratvena ṛṣante vai bhūtādīnṛṣikāstataḥ ṛṣikāṇāṃ sutā ye tu vijñeyā ṛṣiputrakāḥ //
Those who, by their superior (spiritual) status, are called ‘ṛṣis’—beginning with the primordial beings such as Bhūta—are therefore termed ṛṣikās; and those born as the sons of the ṛṣikās are to be understood as ‘ṛṣiputrakas’ (sons of sages).
It does not describe Pralaya directly; it clarifies a technical classification of sages and their descendants used in Puranic accounts of creation-era beings and lineages.
By defining who counts as ṛṣi, ṛṣikā, and ṛṣiputraka, it supports correct recognition of spiritual authority—important for kings and householders when honoring teachers, performing gifts (dāna), and following counsel in dharma and ritual.
No Vāstu or iconographic rule is stated; the ritual takeaway is classificatory—identifying eligible sage-lineages referenced in rites, genealogical recitations, and honorific protocols.