Matsya Purana — The Tale of Brahmadatta: Past-life Memory
द्विजेभ्यः श्रावयेद्यो वा शृणोत्यथ पठेत्तु वा कल्पकोटिशतं साग्रं ब्रह्मलोके महीयते //
dvijebhyaḥ śrāvayedyo vā śṛṇotyatha paṭhettu vā kalpakoṭiśataṃ sāgraṃ brahmaloke mahīyate //
Whoever causes it to be recited to the twice-born, or else listens to it, or even recites it—he is honored in Brahmā’s world for a full hundred crores of kalpas (and more).
It does not describe Pralaya directly; it uses cosmic time units (kalpa) to express the vast, creation-scale duration of the spiritual reward gained by hearing/reciting the Purana.
It frames śravaṇa (listening), pāṭha (recitation), and śrāvaṇa/adhyāpana (arranging a learned recitation for qualified dvijas) as dharmic acts—practices a householder or patron-king can support through sponsorship, public readings, and personal study.
No Vāstu or temple-building rule is stated; the ritual takeaway is the efficacy of Purāṇa-śravaṇa and pāṭha as a meritorious religious observance leading to exalted posthumous honor in Brahmaloka.