Matsya Purana — Ekoddiṣṭa Śrāddha
यावदब्दं तु यो दद्याद् उदकुम्भं विमत्सरः प्रेतायान्नसमायुक्तं सो ऽश्वमेधफलं लभेत् //
yāvadabdaṃ tu yo dadyād udakumbhaṃ vimatsaraḥ pretāyānnasamāyuktaṃ so 'śvamedhaphalaṃ labhet //
Whoever, free from envy, gives a water-pot (udakumbha) for the span of a year, together with food meant for the preta, attains the merit that is declared to be the fruit of the Aśvamedha sacrifice.
This verse does not address Pralaya; it teaches dharma through funerary charity, stating that sustained water-pot donation with food for a departed spirit yields very high merit.
It frames a practical householder/royal duty: performing compassionate, envy-free dāna for the departed (preta), emphasizing ongoing support (for a year) and proper accompaniment (food), which the text equates in merit to major royal sacrifices.
The ritual point is udakumbha-dāna (donation of a water vessel) combined with anna for the preta—highlighting correct śrāddha-style charity rather than temple architecture or Vāstu.