Matsya Purana — The Procedure and Merit of the Śubha-Saptamī Vrata
यावत्समाः सप्त नरः करोति यः सप्तमीं सप्तविधानयुक्ताम् स सप्तलोकाधिपतिः क्रमेण भूत्वा पदं याति परं मुरारेः //
yāvatsamāḥ sapta naraḥ karoti yaḥ saptamīṃ saptavidhānayuktām sa saptalokādhipatiḥ krameṇa bhūtvā padaṃ yāti paraṃ murāreḥ //
A man who, for seven years, observes the Saptamī rite endowed with its seven prescribed constituents, becomes in due course the lord of the seven worlds, and thereafter attains the supreme abode of Murāri (Vishnu).
This verse does not describe Pralaya; it teaches vrata-phala (the spiritual and cosmic rewards of observing the Saptamī vow), culminating in attainment of Vishnu’s supreme abode.
It frames disciplined religious observance as a dharmic duty: a householder (and by extension a king) who maintains a structured vow over time gains worldly sovereignty (symbolized as lordship over the seven worlds) and ultimately spiritual liberation through Vishnu.
The significance is ritual: the Saptamī is to be performed with a “sevenfold procedure” (sapta-vidhāna), emphasizing correct, complete observance rather than temple-architecture rules.