Matsya Purana — Catalogue of the Eighteen Puranas
मार्कण्डेयेन कथितं तत्सर्वं विस्तरेण तु पुराणं नवसाहस्रं मार्कण्डेयम् इहोच्यते //
mārkaṇḍeyena kathitaṃ tatsarvaṃ vistareṇa tu purāṇaṃ navasāhasraṃ mārkaṇḍeyam ihocyate //
All that was expounded by Mārkaṇḍeya—indeed in full detail—is here spoken of as the “Mārkaṇḍeya Purāṇa”, a Purāṇa consisting of nine thousand verses.
This verse does not discuss pralaya; it is a bibliographic note identifying the Mārkaṇḍeya Purāṇa and stating its traditional extent as 9,000 verses.
Indirectly: by clarifying Purāṇic sources and their scope, it supports dharma-based conduct by pointing readers to authoritative narratives and teachings preserved in recognized Purāṇas.
No explicit vastu/temple or ritual procedure is mentioned; the focus is on textual attribution and the stated verse-count of the Mārkaṇḍeya Purāṇa.