Matsya Purana — The Aśūnyaśayana Vrata
एवं सम्पूज्य गोविन्दम् अश्नीयात्तैलवर्जितम् नक्तमक्षारलवणं यावत्तत्स्याच्चतुष्टयम् //
evaṃ sampūjya govindam aśnīyāttailavarjitam naktamakṣāralavaṇaṃ yāvattatsyāccatuṣṭayam //
Thus, having duly worshipped Govinda, one should eat food free from oil; and one should take the night-meal without alkaline additives (akṣāra) and without salt—maintaining this discipline for a set of four (days/nights).
This verse is not about Pralaya; it prescribes a vrata discipline—after worshipping Govinda, one follows specific dietary restrictions for a fourfold period.
It reflects the householder/royal duty of observing regulated worship and self-restraint: devotion (Govinda-pūjā) paired with controlled diet (no oil, no alkali, no salt) as part of dharmic practice.
The ritual significance is vrata-procedure: perform Govinda worship first, then keep a disciplined night-meal (naktabhojana) with specified exclusions, sustained for a catuṣṭaya (four-unit observance).