Matsya Purana — Saptamī Sacred Bath and the Mṛtavatsābhiṣeka Rite for Pacifying Misfortune an...
एतन्महापातकनाशनं स्यात् परं हितं बालविवर्धनं च शृणोति यश्चैनमनन्यचेतास् तस्यापि सिद्धिं मुनयो वदन्ति //
etanmahāpātakanāśanaṃ syāt paraṃ hitaṃ bālavivardhanaṃ ca śṛṇoti yaścainamananyacetās tasyāpi siddhiṃ munayo vadanti //
This becomes a destroyer of the great sins; it is supremely beneficial and promotes the well-being and growth of children. Whoever listens to it with an undivided mind—the sages declare of him too the attainment of success (spiritual accomplishment).
This verse does not discuss pralaya directly; it emphasizes the purifying power and merit (phala) of hearing a sacred teaching that removes great sins and grants siddhi.
It supports the dharmic duty of śravaṇa (attentive listening to sacred instruction) as a practical household virtue—promoting family welfare (including children) while also purifying moral faults and strengthening spiritual discipline.
No specific Vastu or temple-building rule is stated; the ritual takeaway is the efficacy of focused listening/recitation as a sin-destroying, welfare-giving practice endorsed by sages.