Matsya Purana — Nārāyaṇa as Haṃsa in the Cosmic Ocean: Vedic Yajña-Puruṣa and Mārkaṇḍeya’s Vi...
सम्प्रविष्टः पुनः कुक्षिं मार्कण्डेयो ऽतिविस्मयः तथैव तु पुनर्भूयो विजानन्स्वप्नदर्शनम् //
sampraviṣṭaḥ punaḥ kukṣiṃ mārkaṇḍeyo 'tivismayaḥ tathaiva tu punarbhūyo vijānansvapnadarśanam //
Markandeya, filled with utter amazement, again entered the womb; and once more he recognized that what he had seen was like a dream-vision.
It frames the pralaya experience as a divinely induced, dream-like vision—suggesting cosmic dissolution can be revealed through māyā-like perception rather than ordinary waking reality.
Indirectly, it teaches discernment (viveka): even overwhelming experiences can be transient and deceptive, so one should anchor duty (dharma) in steadiness rather than in fear or spectacle.
No direct Vāstu or ritual procedure is stated; the takeaway is contemplative—visions and omens should be interpreted carefully, not treated as concrete prescriptions without scriptural context.