Matsya Purana — Uma’s Austerities and the Slaying of the Deceiver Asura ĀḌi
मेढ्रे वज्रास्त्रमादाय दानवं तमसूदयत् अबुध्यद्वीरको नैव दानवेन्द्रं निषूदितम् //
meḍhre vajrāstramādāya dānavaṃ tamasūdayat abudhyadvīrako naiva dānavendraṃ niṣūditam //
Seizing the Vajrāstra, the thunderbolt-weapon at his loins, he struck down that Dānava. Yet the hero Vīraka did not realize that the lord of the Dānavas had been slain.
This verse does not discuss Pralaya; it belongs to a martial-heroic narrative describing the slaying of a Dānava using a divine weapon (vajrāstra).
Indirectly, it reflects the Purāṇic ideal of kṣātra-dharma—protecting order by confronting destructive forces (here, Dānavas). The emphasis is on decisive action and the potency of sanctioned weapons in upholding dharma.
No Vāstu or temple-architecture rule appears here; the technical element is astravidyā (weapon-lore), specifically the vajrāstra, highlighting ritualized/divine weapon traditions rather than building prescriptions.