Matsya Purana — Nārāyaṇa as Haṃsa in the Cosmic Ocean: Vedic Yajña-Puruṣa and Mārkaṇḍeya’s Vi...
ततस्त्वां घोरतपसा प्रावृणोदमितौजसम् उक्तवानहमात्मस्थं महर्षिम् अमितौजसम् //
tatastvāṃ ghoratapasā prāvṛṇodamitaujasam uktavānahamātmasthaṃ maharṣim amitaujasam //
Then, by fierce austerity, I encompassed you—one of immeasurable splendor; and I addressed that great seer, steadfast within the Self, endowed with boundless might.
It emphasizes tapas (austerity) as a force that can “envelop” or empower a being of great radiance—typical of the spiritual preparation that precedes major cosmic events like pralaya in Purāṇic narration.
It models inner discipline: even when acting outwardly, one should be ātmastha (self-anchored). For kings and householders, the implied ethic is governance and duty supported by self-control and spiritual practice.
No direct Vāstu/temple rule is stated; the ritual takeaway is the primacy of tapas and inward steadiness (ātmasthatva) as the qualifying foundation for sacred speech, counsel, and consecratory intent.