Matsya Purana — Maya’s War-Counsel to the Danavas and the Moonlit Revels in Tripura
इति तत्र पुरे ऽमरद्विषाणां सपदि हि पश्चिमकौमुदी तदासीत् / रणशिरसि पराभविष्यतां वै भवतुरगैः कृतसंक्षया अरीणाम् //
iti tatra pure 'maradviṣāṇāṃ sapadi hi paścimakaumudī tadāsīt / raṇaśirasi parābhaviṣyatāṃ vai bhavaturagaiḥ kṛtasaṃkṣayā arīṇām //
Thus, in that city of the gods’ enemies, a “western moonlight,” dim as at dusk, suddenly fell. And on the very field of battle, those destined for defeat had their foes cut down to the last by the steeds (and riders) of Bhava (Śiva).
It does not describe cosmic Pralaya; it uses an image of “western moonlight” as an omen-like metaphor for decline in a battle context, not universal dissolution.
Indirectly, it underscores the Purāṇic ethic that adharma-aligned aggressors (“enemies of the devas”) meet swift defeat; for kings, it implies righteous alliances and protection of dharma lead to victory and stability.
No Vāstu or ritual procedure is taught in this verse; its technical focus is martial imagery and the invocation of Bhava (Śiva) as a decisive power in war.