Matsya Purana — Account of the Manvantaras: Manus
इक्ष्वाकुप्रमुखाश्चास्य दश पुत्राः स्मृता भुवि मन्वन्तरेषु सर्वेषु सप्त सप्त महर्षयः //
ikṣvākupramukhāścāsya daśa putrāḥ smṛtā bhuvi manvantareṣu sarveṣu sapta sapta maharṣayaḥ //
Beginning with Ikṣvāku, ten sons of his are remembered on earth; and in every Manvantara there are, indeed, seven great Ṛṣis (the Saptarṣis).
It does not describe Pralaya directly; it establishes the recurring cosmic administration of time—each Manvantara has a fixed structure, including a set of seven great sages, implying ordered continuity across cycles.
By grounding kingship in lineage (Ikṣvāku and the Manu tradition) and in the guidance of the Saptarṣis, it implies that rulers and householders should align conduct with dharma preserved by venerable sages and inherited tradition.
No Vāstu or temple-rule detail is stated; the ritual takeaway is the Purāṇic principle that every age is regulated by authoritative sages, who are the custodians of rites, calendars, and dharma.