Matsya Purana — Vishnu’s Battle with Mathana
शुम्भो ऽपि विष्णुं परिघेण मूर्ध्नि प्रमृष्टरत्नौघविचित्रभासा तौ दानवाभ्यां विषमैः प्रहारैर् निपेतुरुर्व्यां घनपावकाभौ //
śumbho 'pi viṣṇuṃ parigheṇa mūrdhni pramṛṣṭaratnaughavicitrabhāsā tau dānavābhyāṃ viṣamaiḥ prahārair nipetururvyāṃ ghanapāvakābhau //
Śumbha too struck Viṣṇu on the head with an iron bludgeon; their bodies shone with a variegated radiance, as if polished by streams of jewels. Then, assailed by those two demons with unequalled blows, the two fell upon the earth—like a cloud and fire crashing down together.
This verse is not about pralaya; it is a battle-description verse, using cosmic-style imagery (cloud and fire) to convey the force of the blows and the fall to earth.
Indirectly, it reflects the Purāṇic ethic of protecting order (dharma) against disruptive forces; the narrative frames conflict as a struggle where divine power confronts demonic aggression, a motif later applied to righteous kingship as defense of social order.
No explicit Vāstu or ritual procedure is stated; the verse is primarily poetic combat narration, notable for its simile (cloud and fire) and jewel-like radiance imagery rather than technical temple or rite instructions.