Matsya Purana — Vrata-Ṣaṣṭhī: The Sixty Sacred Vows
दशम्याम् एकभक्ताशी समान्ते दशधेनुदः दिशश्च काञ्चनैर्दद्याद् ब्रह्माण्डाधिपतिर्भवेत् एतद् विश्वव्रतं नाम महापातकनाशनम् //
daśamyām ekabhaktāśī samānte daśadhenudaḥ diśaśca kāñcanairdadyād brahmāṇḍādhipatirbhavet etad viśvavrataṃ nāma mahāpātakanāśanam //
On the tenth lunar day, eating only once, one should at the conclusion make a gift of ten cows and also give gold to the quarters (as offerings to the deities of the directions). He becomes, as it were, a lord over the brahmāṇḍa, the cosmic egg (the universe). This is called the Viśvavrata, the “Universal Vow,” and it destroys even great sins.
It does not describe Pralaya directly; it uses the cosmological term “brahmāṇḍa” to express the vow’s supreme merit—symbolic ‘lordship over the universe’ as a spiritual reward.
It frames household/royal dharma as disciplined observance (ekabhakta on Daśamī) combined with public generosity (dāna of cows and gold), presenting charity and self-restraint as key purificatory duties.
Ritually, it prescribes a Daśamī vrata with concluding donations, including offerings “to the directions,” reflecting dik-oriented worship common in Vedic-Puranic rites (though not a Vāstu/temple-construction rule in itself).