Matsya Purana — Vrata-Ṣaṣṭhī: The Sixty Sacred Vows
आषाढादिव्रतं यस्तु वर्जयेन्नखकर्तनम् वार्ताकं च चतुर्मासं मधुसर्पिर्घटान्वितम् //
āṣāḍhādivrataṃ yastu varjayennakhakartanam vārtākaṃ ca caturmāsaṃ madhusarpirghaṭānvitam //
Whoever undertakes the vow beginning in Āṣāḍha should refrain from cutting the nails; and throughout the four months of Caturmāsa he should also abstain from vārtāka (eggplant), maintaining the vow with offerings of honey and ghee kept in pots.
This verse does not address Pralaya; it is a Dharma-oriented instruction on Caturmāsa vow-discipline, emphasizing bodily restraint and regulated diet as part of religious observance.
It frames household/royal conduct around self-restraint during Caturmāsa: avoiding nail-cutting and certain foods, and sustaining devotional offerings (honey and ghee). Such discipline is presented as a model of dharmic living and public exemplarity.
The ritual element is the use of ghaṭas (pots/jars) associated with madhu and sarpiḥ—indicative of prescribed offering materials and vessel-based ritual setup during the vow, rather than Vāstu or temple-construction rules.