Matsya Purana — Vrata-Ṣaṣṭhī: The Sixty Sacred Vows
अश्वत्थं भास्करं गङ्गां प्रणम्यैकत्र वाग्यतः एकभक्तं नरः कुर्याद् अब्दमेकं विमत्सरः //
aśvatthaṃ bhāskaraṃ gaṅgāṃ praṇamyaikatra vāgyataḥ ekabhaktaṃ naraḥ kuryād abdamekaṃ vimatsaraḥ //
Having bowed in reverence to the sacred aśvattha tree, the Sun, and the river Gaṅgā in one place, and having restrained his speech (remaining in one spot), a man—free from malice—should observe for one full year the discipline of taking a single meal a day.
This verse does not address pralaya directly; it focuses on dharmic self-discipline (vrata) and merit through reverence to sacred symbols (Aśvattha, Sūrya, Gaṅgā) and regulated living.
It prescribes a householder-friendly austerity: controlled speech, non-malice, and the ekabhakta vow for a year—framing personal restraint as a core dharma that supports ethical governance and social harmony.
Ritually, it highlights worship of natural and cosmic sanctities (tree, Sun, sacred river) and the discipline of vāg-yama and ekabhakta—useful for planning vrata routines and pilgrimage/river-ritual observances rather than temple architecture rules.