Matsya Purana — The Rite of the Vibhūti-Dvādaśī Vow
एकादश्यां निराहारः समभ्यर्च्य जनार्दनम् द्वादश्यां द्विजसंयुक्तः करिष्ये भोजनं विभो //
ekādaśyāṃ nirāhāraḥ samabhyarcya janārdanam dvādaśyāṃ dvijasaṃyuktaḥ kariṣye bhojanaṃ vibho //
“On the Ekādaśī day I shall remain without food and duly worship Janārdana; then, on the Dvādaśī day, in the company (and with the sanction) of Brahmins, I shall take my meal, O Lord.”
This verse is not about pralaya; it teaches vrata-dharma—fasting on Ekādaśī, worship of Vishnu, and the proper, disciplined breaking of the fast on Dvādaśī.
It models regulated self-control and piety: observing Ekādaśī with fasting and worship, then taking food on Dvādaśī in a socially and ritually proper way—“with Brahmins,” implying guidance, auspiciousness, and dharmic conduct expected of householders (and rulers as exemplars).
The ritual significance is the Ekādaśī fast (nirāhāra) and Dvādaśī pāraṇa (breaking the fast) after worship of Janārdana, ideally in the presence/association of Brahmins—highlighting correct sequencing and ritual propriety rather than Vāstu or temple-measurement rules.