Matsya Purana — Cosmography of Śākadvīpa and Successive Dvīpas: Mountains
तासां तु नामधेयानि परिमाणं तथैव च न शक्यं परिसंख्यातुं पुण्यास्ताः सरिदुत्तमाः //
tāsāṃ tu nāmadheyāni parimāṇaṃ tathaiva ca na śakyaṃ parisaṃkhyātuṃ puṇyāstāḥ sariduttamāḥ //
But their names—and their extent as well—cannot be fully enumerated; those supreme rivers are holy and merit-bestowing.
This verse is not describing Pralaya; it emphasizes the immeasurable number and extent of sacred rivers, highlighting the boundless field of merit (puṇya) available through tirtha traditions.
It supports dharmic conduct by valuing pilgrimage, purification, and charity connected with sacred waters—practices a householder may undertake and a king may protect by maintaining access, safety, and sanctity of tirthas.
Ritually, it underscores the primacy of river-tirthas for स्नान (snāna, sacred bathing) and purification; architecturally it indirectly supports placing ghats, temples, and tirtha facilities near holy rivers due to their exceptional sanctity.