Matsya Purana — Narasimha’s Victory over Hiraṇyakaśipu and the Catalogue of Apocalyptic Omens
मेदिन्यां कम्पमानायां दैत्येन्द्रेण महात्मना महीधरा नागगणा निपेतुरमितौजसः //
medinyāṃ kampamānāyāṃ daityendreṇa mahātmanā mahīdharā nāgagaṇā nipeturamitaujasaḥ //
As the Earth shook under the onslaught of the great-souled lord of the Daityas, mighty mountain-bearers and hosts of Nāgas, of immeasurable strength, fell down.
It uses Pralaya-like imagery—Earth trembling and the collapse of mountains and Nāga hosts—to convey a cosmic-scale disturbance caused by a Daitya overlord, echoing the Purāṇic theme that adharma-driven power destabilizes the world.
Indirectly, it functions as a warning motif: when destructive, unrighteous force dominates (symbolized by the Daitya chief), even the foundations of the world ‘shake.’ In Matsya Purana ethics, a ruler’s dharma is to prevent such destabilization by protecting order (ṛta/dharma) and restraining violent excess.
No direct Vāstu or ritual rule is stated, but the verse foregrounds seismic instability (Earth trembling, mountains collapsing), which later Vāstu-oriented readings treat as a cautionary symbol for choosing stable land and ensuring firm foundations in sacred and civic construction.