Matsya Purana — Procedure for Going to Prayaga and the Greatness of the Ganga
तत्र ते द्वादशादित्यास् तपन्ति रुद्रसंश्रिताः निर्दहन्ति जगत्सर्वं वटमूलं न दह्यते //
tatra te dvādaśādityās tapanti rudrasaṃśritāḥ nirdahanti jagatsarvaṃ vaṭamūlaṃ na dahyate //
There the twelve Ādityas, abiding in association with the Rudras, blaze forth; they burn up the entire universe—yet the root of the banyan tree is not burned.
It depicts pralaya as a universe-consuming conflagration driven by divine solar powers (Ādityas) aligned with Rudras, while hinting at an imperishable remainder—symbolized by the banyan root—that survives dissolution.
By stressing that even cosmic structures dissolve, it underlines the Matsya Purana ethic of non-attachment and dharmic steadiness: rulers and householders should govern/act righteously knowing worldly forms are transient, while safeguarding enduring principles (dharma) that ‘remain’ like the banyan root.
Direct Vāstu rules are not stated, but the banyan root functions as a ritual-cosmic symbol of stability and continuity—often echoed in sacred-grove practice and temple ecology—suggesting the idea of an enduring ‘root’ or axis even amid cycles of destruction.