Matsya Purana — The Maheshvara Vow: Śiva-Caturdaśī Vrata
मार्गशीर्षत्रयोदश्यां सितायामेकभोजनः प्रार्थयेद्देवदेवेशं त्वामहं शरणं गतः //
mārgaśīrṣatrayodaśyāṃ sitāyāmekabhojanaḥ prārthayeddevadeveśaṃ tvāmahaṃ śaraṇaṃ gataḥ //
On the bright (waxing) thirteenth day (Trayodaśī) of Mārgaśīrṣa, taking only a single meal, one should pray to the Lord of gods: “You are my refuge; to you I have surrendered.”
This verse is not about Pralaya; it teaches a devotional vow (eka-bhojana) and surrender to the Supreme Lord, emphasizing ritual discipline rather than cosmic dissolution.
It prescribes a regulated observance on a specific tithi—taking one meal and offering prayer—modeling self-control and piety expected of householders and rulers who uphold dharma through disciplined worship.
The ritual significance is tithi-based worship: on Mārgaśīrṣa Śukla Trayodaśī one performs a vrata with eka-bhojana and a surrender-prayer to Deva-Deveśa; no Vāstu or temple-construction detail is stated in this verse.