Matsya Purana — Cosmography of Śākadvīpa and Successive Dvīpas: Mountains
त्रिंशद्वर्षसहस्राणि मानसीं सिद्धिमास्थिताः सुखमायुश्च रूपं च धर्मैश्वर्यं तथैव च //
triṃśadvarṣasahasrāṇi mānasīṃ siddhimāsthitāḥ sukhamāyuśca rūpaṃ ca dharmaiśvaryaṃ tathaiva ca //
For thirty thousand years they remain established in mental perfection (mānasī siddhi), enjoying happiness, long life, beauty, and likewise the prosperity that comes through dharma.
This verse does not describe pralaya; it states the merit-result (phala) of dharmic practice—mental attainment, happiness, longevity, beauty, and dharma-born prosperity.
It reinforces the Matsya Purana’s ethic that sustained dharma (right conduct, charity, vows, ritual duty) yields tangible and inner results—well-being, long life, good reputation/beauty, and stable prosperity—key aims for householders and rulers alike.
No direct Vastu or iconographic rule appears here; the verse functions as a general phala-śruti emphasizing the rewards of dharma/merit that may arise from ritual observances described in the surrounding context.