Matsya Purana — Procedure for Going to Prayaga and the Greatness of the Ganga
ततः स्वर्गात्परिभ्रष्टो जम्बूद्वीपपतिर्भवेत् तीर्थानां तु परं तीर्थं नदीनां तु महानदी मोक्षदा सर्वभूतानां महापातकिनामपि //
tataḥ svargātparibhraṣṭo jambūdvīpapatirbhavet tīrthānāṃ tu paraṃ tīrthaṃ nadīnāṃ tu mahānadī mokṣadā sarvabhūtānāṃ mahāpātakināmapi //
Thereupon, even one who has fallen away from heaven may become a lord of Jambūdvīpa. This is the supreme tīrtha among all tīrthas, and among rivers it is the Great River; it bestows mokṣa upon all beings, even upon those stained by great sins.
This verse does not describe pralaya directly; it teaches the salvific power of a supreme tīrtha and a “Great River,” emphasizing purification and liberation rather than cosmic dissolution.
It supports the Purāṇic ideal that householders and rulers gain dharmic merit through tīrtha-yātrā, honoring sacred rivers and pilgrimage disciplines; such acts are portrayed as powerful enough to elevate status (even to sovereignty) and remove grave sin.
The ritual significance is the primacy of tīrtha-sevā—bathing, offerings, and observance at a supreme pilgrimage ford and major river—implying that proper river-rites and tīrtha observances are central to purification and mokṣa in this section.