Matsya Purana — Narasimha’s Victory over Hiraṇyakaśipu and the Catalogue of Apocalyptic Omens
शैलसंवर्ष्मणस् तस्य शरीरे शरवृष्टिभिः अवध्यस्य मृगेन्द्रस्य न व्यथां चक्रुराहवे //
śailasaṃvarṣmaṇas tasya śarīre śaravṛṣṭibhiḥ avadhyasya mṛgendrasya na vyathāṃ cakrurāhave //
In battle, showers of arrows caused no pain to that lion-king—invulnerable—whose body was as hard as a mountain.
This verse does not discuss Pralaya; it focuses on battlefield description, emphasizing an enemy’s invulnerability and the futility of ordinary weapons.
Indirectly, it reflects Rajadharma through the realism of conflict: a ruler’s duty includes discerning effective strategy and recognizing when conventional force (like volleys of arrows) is insufficient against an invulnerable foe.
No Vāstu or ritual procedure is stated; the imagery is metaphorical—'mountain-like body'—used to convey hardness and invulnerability rather than architectural instruction.