Matsya Purana — Brahmā–Gāyatrī as a Divine Pair and the Early Genealogies of Creation
उत्तानपादो ऽजनयत् सूनृतायां प्रजापतिः ध्रुवो वर्षसहस्राणि त्रीणि कृत्वा तपः पुरा //
uttānapādo 'janayat sūnṛtāyāṃ prajāpatiḥ dhruvo varṣasahasrāṇi trīṇi kṛtvā tapaḥ purā //
The Prajāpati Uttānapāda begot a son in Sūnṛtā; and Dhruva, in ancient times, performed austerity for three thousand years.
This verse does not describe Pralaya; it preserves genealogical memory by linking a Prajāpati (Uttānapāda) to Dhruva and highlighting tapas as a cosmic-moral force sustaining order.
It presents the royal line as grounded in dharma: progenitors maintain lineage responsibly, and exemplary figures like Dhruva embody self-discipline (tapas) as an ideal for rulers and householders alike.
No Vāstu or temple-building rule is stated here; the ritual takeaway is the emphasis on tapaḥ (austerity) as a recognized spiritual practice within Purāṇic tradition.