Matsya Purana — Purūravas Witnesses the Sports of Apsarases and Gandharvas; Attains the Grace...
कृतदेवार्चनो राजा तथा हुतहुताशनः सर्वान्कामानवाप्तो ऽसौ वरदानेन केशवात् //
kṛtadevārcano rājā tathā hutahutāśanaḥ sarvānkāmānavāpto 'sau varadānena keśavāt //
That king—having duly worshiped the gods and offered oblations into the sacred fire—attained all desired aims through the boon-giving grace of Keśava (Viṣṇu).
It does not discuss pralaya directly; it emphasizes ritual worship (deva-archana) and fire-offerings (homa) as means to attain desired outcomes through Viṣṇu’s grace.
It presents a core Rajadharma/householder ideal: a ruler (and by extension a gṛhastha) should uphold worship and sacrificial fire-offerings, and such disciplined dharma is said to yield prosperity and fulfillment under Keśava’s favor.
The ritual significance is explicit: deva-archana (formal worship) and homa (oblations into Agni) are portrayed as efficacious acts whose fruit culminates in Viṣṇu’s boon-bestowal.