Matsya Purana — The Glory of Prayaga: Pilgrimage
योजनानां सहस्रेषु गङ्गायाः स्मरणान्नरः अपि दुष्कृतकर्मा तु लभते परमां गतिम् //
yojanānāṃ sahasreṣu gaṅgāyāḥ smaraṇānnaraḥ api duṣkṛtakarmā tu labhate paramāṃ gatim //
Even from thousands of yojanas away, a man—though burdened with sinful deeds—attains the highest state merely by remembering the Gaṅgā.
This verse does not describe Pralaya directly; it teaches tirtha-mahātmyā—how sacred remembrance (smaraṇa) of the Ganga grants spiritual upliftment irrespective of physical distance.
It supports the householder/kingly ethic that inner devotion and regular remembrance of sacred realities (like the Ganga) are accessible practices for purification, even when one cannot travel for pilgrimage due to duties of governance or family.
No temple/ वास्तु rule is stated; the ritual takeaway is that mental worship—smaraṇa of the Ganga—functions as a potent substitute or support to physical pilgrimage rites, emphasizing intention and remembrance as spiritually efficacious.