Matsya Purana — Prayaga Mahatmya: Trimurti Presence
सप्तद्वीपाः समुद्राश्च पर्वताश्च महीतले रक्षमाणाश्च तिष्ठन्ति यावदाभूतसंप्लवम् //
saptadvīpāḥ samudrāśca parvatāśca mahītale rakṣamāṇāśca tiṣṭhanti yāvadābhūtasaṃplavam //
Upon the earth’s surface, the seven continents, the oceans, and the mountains stand firm as guardians, enduring so long as the great dissolution of beings—the cosmic deluge—has not arrived.
It states that the world’s structured geography—continents, oceans, and mountains—remains stable and protective until the onset of the great cosmic inundation (pralaya), when that order is finally withdrawn.
By portraying mountains and oceans as ‘guardians’ of order, the verse implicitly supports the Purāṇic ethic that rulers and householders should likewise preserve stability—protecting people, boundaries, and dharma—until circumstances of unavoidable collapse arise.
Direct Vāstu or ritual rules are not stated, but the verse reinforces a key Vāstu premise: stable cosmic order (directions, landforms, and natural boundaries) is foundational—temple/town planning ideally respects mountains, waters, and the earth’s protective layout.