Matsya Purana — Saptamī Sacred Bath and the Mṛtavatsābhiṣeka Rite for Pacifying Misfortune an...
एतत्सर्वं समाख्यातं सप्तमीस्नानमुत्तमम् सर्वदुष्टोपशमनं बालानां परमं हितम् //
etatsarvaṃ samākhyātaṃ saptamīsnānamuttamam sarvaduṣṭopaśamanaṃ bālānāṃ paramaṃ hitam //
Thus, all of this has been explained—the excellent rite of bathing on the Saptamī (seventh lunar day). It pacifies every harmful influence and is supremely beneficial for children.
This verse does not address Pralaya; it concludes a ritual instruction, praising Saptamī bathing as a purifier that calms harmful influences.
It supports the householder’s duty of protecting family welfare—especially children—through dharmic observances, recommending Saptamī snāna as a protective, merit-giving practice.
The significance is ritual (not architectural): Saptamī snāna is presented as an ‘uttama’ purification rite that mitigates inauspiciousness and promotes children’s well-being.