Matsya Purana — Catalogue of the Eighteen Puranas
भविष्याणां च कल्पानां श्रूयते यत्र विस्तरः तद्ब्रह्माण्डपुराणं च ब्रह्मणा समुदाहृतम् //
bhaviṣyāṇāṃ ca kalpānāṃ śrūyate yatra vistaraḥ tadbrahmāṇḍapurāṇaṃ ca brahmaṇā samudāhṛtam //
That Purāṇa in which an extensive account is heard concerning the future kalpas (aeons) is the Brahmāṇḍa Purāṇa, as proclaimed by Brahmā.
Indirectly, it situates pralaya within the larger kalpa-cycle framework: the Brahmāṇḍa Purāṇa is identified as a text that elaborates future kalpas, i.e., forthcoming cosmic cycles in which creations and dissolutions recur.
It does so by guiding seekers to the appropriate scripture for a topic: a king or householder looking for dharma across changing ages would consult Purāṇas by their specialization—here, the Brahmāṇḍa Purāṇa for future kalpa-oriented teachings.
No direct Vāstu or ritual rule is stated; the significance is classificatory—identifying which Purāṇa to consult for detailed cosmological timelines that often frame ritual calendars and age-based observances.