Matsya Purana — Division of Bhārata-varṣa
इन्द्रद्वीपः कशेरुश्च ताम्रपर्णो गभस्तिमान् नागद्वीपस्तथा सौम्यो गन्धर्वस्त्वथ वारुणः //
indradvīpaḥ kaśeruśca tāmraparṇo gabhastimān nāgadvīpastathā saumyo gandharvastvatha vāruṇaḥ //
“(These are the divisions:) Indradvīpa and Kaśeru; Tāmraparṇa and Gabhastimān; likewise Nāgadvīpa and Saumya; then Gandharva and also Vāruṇa.”
This verse is not describing pralaya; it functions as a cosmographic catalogue, naming dvīpas/regions within the ordered world-structure (bhū-maṇḍala) that persists across cycles.
Indirectly: by mapping the world into named regions, the Purana supplies a sacred-geographical framework used in royal ideology (universal sovereignty, pilgrimage networks) and household rites (tīrtha-oriented vows and directional sanctity).
No explicit Vāstu rule appears here, but such cosmographic enumerations underpin ritual geography—directions, mandala-world correspondences, and the idea that temple space mirrors the ordered cosmos.