Matsya Purana — Manvantaras
ब्रह्मचर्यं तपो मौनं निराहारत्वमेव च इत्येतत्तपसो रूपं सुघोरं तु दुरासदम् //
brahmacaryaṃ tapo maunaṃ nirāhāratvameva ca ityetattapaso rūpaṃ sughoraṃ tu durāsadam //
Celibacy (brahmacarya), austerity, silence (mauna), and even fasting—these are the forms of tapas; indeed, this discipline is exceedingly fierce and difficult to undertake.
This verse does not describe pralaya directly; it defines intense tapas—celibacy, silence, and fasting—as a powerful spiritual discipline used for purification and attainment.
It frames self-control as a core dharmic tool: even rulers and householders may adopt moderated forms of brahmacarya, mauna, and regulated fasting to govern the senses, uphold vows, and strengthen ethical conduct.
No vastu or temple-construction rule is stated here; the ritual takeaway is that vows like mauna (silence) and nirāhāra (fasting) are recognized as rigorous components of tapas in Puranic practice.