Matsya Purana — The Legend of Acchodā: Pitṛloka
अग्निष्वात्ता इति ख्याता यज्वानो यत्र संस्थिताः अच्छोदा नाम तेषां तु मानसी कन्यका नदी //
agniṣvāttā iti khyātā yajvāno yatra saṃsthitāḥ acchodā nāma teṣāṃ tu mānasī kanyakā nadī //
There dwell the sacrificial sages renowned as the Agniṣvāttas; and for them there is a river named Acchodā—born of the mind, a maiden-like, pure stream.
It does not describe Pralaya directly; it highlights Puranic cosmography by locating a divine community (Agniṣvāttas) and a mind-born sacred river, emphasizing the subtle, non-physical origins of certain tirthas.
By foregrounding yajña-performing beings and a sacred river, it supports the Matsya Purana’s broader ethic that householders and rulers sustain order through sacrifice, ancestral reverence (pitṛ-tarpaṇa), and tirtha-related rites.
The ritual takeaway is the prominence of yajña and pitṛ-related sanctity: such rivers function as tirthas suitable for offerings to ancestors and purification rites, even though no explicit Vastu/temple-building rule is stated in this verse.