Matsya Purana — Manvantaras
तपसश्च तथारण्ये साधुर्वैखानसः स्मृतः यतमानो यतिः साधुः स्मृतो योगस्य साधनात् //
tapasaśca tathāraṇye sādhurvaikhānasaḥ smṛtaḥ yatamāno yatiḥ sādhuḥ smṛto yogasya sādhanāt //
Likewise, one who practices tapas (austerity) in the forest is regarded as a true Vaikhānasa, a forest-ascetic. And the disciplined yati, striving with restraint, is called a good person, because he undertakes the sādhana—the means—of Yoga.
This verse does not discuss Pralaya; it defines spiritual qualifications—how austerity, forest-dwelling discipline, and yoga-practice characterize a true ascetic.
It offers a standard for recognizing genuine holy persons (sādhus/yatis) whom a king or householder may honor and learn from—those grounded in tapas, restraint, and yoga-sādhana rather than mere outward signs.
No Vāstu or temple-architecture rule is stated here; the ritual takeaway is that authentic sanctity is tied to disciplined practice (tapas and yoga-sādhana), especially in the forest-ascetic (Vaikhānasa) mode.