Matsya Purana — Brahmā’s Four Faces
उत्पतन्त्यास् तदाकारा आलोकनकुतूहलात् सृष्ट्यर्थं यत् कृतं तेन तपः परमदारुणम् //
utpatantyās tadākārā ālokanakutūhalāt sṛṣṭyarthaṃ yat kṛtaṃ tena tapaḥ paramadāruṇam //
As she was emerging and assuming that very form, out of curiosity to behold her own manifestation, he performed—toward the purpose of creation—an austerity exceedingly severe.
It highlights creation (sṛṣṭi) as being propelled by intense tapas—ascetic potency—suggesting that manifesting forms arise through a deliberate, severe spiritual exertion rather than by chance.
It frames disciplined effort (tapas) as the engine of constructive outcomes; by analogy, a king or householder sustains order and prosperity through self-restraint, purposeful action, and commitment to dharmic goals.
No direct Vastu or iconographic rule is stated; the ritual takeaway is the primacy of tapas (austerity/observance) as a prerequisite power for initiating sacred acts and generative undertakings.