Matsya Purana — Soma
न मृतानां गतिः शक्या ज्ञातुं वा पुनरागतिः तपसा हि प्रसिद्धेन किं पुनर्मांसचक्षुषा //
na mṛtānāṃ gatiḥ śakyā jñātuṃ vā punarāgatiḥ tapasā hi prasiddhena kiṃ punarmāṃsacakṣuṣā //
The course of those who have died—and whether they return again—cannot be known. Even by one renowned for austerity (tapas) it is hard to ascertain; how much more so by the mere fleshly eye?
It does not describe Pralaya directly; it emphasizes that unseen transitions—like the dead person’s onward journey—are beyond ordinary sensory proof, a theme that also underlies Purāṇic accounts of cosmic dissolution being knowable chiefly through śāstra and yogic insight.
It urges humility and restraint in claims about unseen results; a king or householder should therefore rely on dharma—śrāddha, dāna, and righteous conduct—rather than speculation, since the dead’s destiny is not verifiable by ordinary observation.
No Vāstu rule is stated; the ritual takeaway is that post-death rites (like śrāddha) are performed on the authority of dharma and śāstra, not because the afterlife outcome can be “seen” with physical eyes.