Matsya Purana — Brahmā–Gāyatrī as a Divine Pair and the Early Genealogies of Creation
अवतीर्यासुरध्वंसी द्वारकाम् अधिवत्स्यति तद्भ्रातुस्तत्समस्य त्वं तदा पुत्रत्वमेष्यसि //
avatīryāsuradhvaṃsī dvārakām adhivatsyati tadbhrātustatsamasya tvaṃ tadā putratvameṣyasi //
Descending to earth as the destroyer of the demons, he will dwell in Dvārakā; and you, at that time, will attain sonship as the child of his brother—one equal to him.
This verse does not describe Pralaya; it focuses on avatāra-prophecy—an incarnate figure who destroys demons and resides in Dvārakā, indicating historical-theological chronology rather than cosmic dissolution.
Indirectly, it reinforces the Purāṇic ideal that adharma (here symbolized by ‘asuras’) is checked by divinely aligned leadership; kings and householders are to uphold dharma in their spheres as part of that larger moral order.
The only place-marker is Dvārakā; while no Vāstu rule is stated, the verse is relevant for contextual SEO around ‘Dvārakā’ as a sacred city and its Purāṇic associations rather than technical temple-building prescriptions.