Matsya Purana — Lineage of the Pitṛs
प्रसादे लोकसृष्ट्यर्थं तपः कार्यं ममान्तिके प्रजापतिस्त्वं भविता दशानामङ्गजो ऽप्यलम् //
prasāde lokasṛṣṭyarthaṃ tapaḥ kāryaṃ mamāntike prajāpatistvaṃ bhavitā daśānāmaṅgajo 'pyalam //
By my grace, for the sake of bringing about the creation of the worlds, you must perform austerity (tapas) in my presence; you shall become a Prajāpati—indeed a progenitor among the ten Prajāpatis—and also a mind-born son, fully empowered.
It emphasizes creation (sṛṣṭi), teaching that cosmic generation is initiated through divine grace and tapas, by which a being is empowered to function as a Prajāpati for producing creatures.
It presents tapas as disciplined effort undertaken for a larger social-cosmic purpose; similarly, kings and householders are expected to practice self-restraint and duty (dharma) to sustain order and prosperity.
No direct Vāstu or temple rule is stated; the ritual takeaway is that tapas performed ‘in the presence’ of the deity/creator is portrayed as a consecrating means to gain authority for world-sustaining functions.