Matsya Purana — Duties of the Four Āśramas and the Power of Mauna
दशैव पूर्वान्दश चापरांस्तु ज्ञातींस्तथात्मानमथैकविंशम् अरण्यवासी सुकृतं दधाति मुक्त्वा त्व् अरण्ये स्वशरीरधातून् //
daśaiva pūrvāndaśa cāparāṃstu jñātīṃstathātmānamathaikaviṃśam araṇyavāsī sukṛtaṃ dadhāti muktvā tv araṇye svaśarīradhātūn //
One who dwells in the forest bestows his store of merit upon twenty-one—ten ancestors, ten descendants, and his own self as the twenty-first—after laying aside in the wilderness the bodily constituents of his frame.
This verse does not describe Pralaya; it teaches the dharmic fruit of forest-dwelling—how austerity and dying/ending life in renunciation is said to uplift one’s lineage through accumulated merit.
It frames the later-life duty (āśrama-dharma): after fulfilling household obligations, one may enter forest-dwelling/renunciation, and that disciplined withdrawal is portrayed as benefiting ancestors and descendants—an ideal even kings are encouraged to honor after ruling.
No Vāstu or temple-building rule appears here; the ritual takeaway is the pitṛ-oriented merit doctrine—ascetic forest-life and relinquishing bodily attachments are said to generate transferable spiritual benefit to one’s lineage.