Matsya Purana — Sādhāraṇa Śrāddha: General Ancestral Rite
तृप्ताञ्ज्ञात्वोदकं दद्यात् सकृद्विप्रकरे तथा उपलिप्ते महीपृष्ठे गोशकृन्मूत्रवारिणा //
tṛptāñjñātvodakaṃ dadyāt sakṛdviprakare tathā upalipte mahīpṛṣṭhe gośakṛnmūtravāriṇā //
Knowing that the guest or recipient has been satisfied, one should then give water; likewise, only once into the hand of a Brāhmaṇa. And the rite is to be performed upon ground plastered with a mixture of cow-dung, cow-urine, and water.
This verse does not discuss Pralaya; it focuses on śauca (ritual cleanliness) and proper procedure in giving water and making offerings after satisfaction is ensured.
It outlines household/ritual etiquette: after feeding or honoring someone, the giver should offer water appropriately, and when dealing with a Brāhmaṇa the giving is to be done properly (once, into the hand), reflecting disciplined dāna and respectful conduct.
The ritual setting is specified: the act should be done on ground purified by plastering with cow-dung, cow-urine, and water—classic śauca practice used to sanctify a space before offerings.