Matsya Purana — The Sarasvata Vrata: Vow for Sweet Speech
सारस्वतं व्रतं यस्तु शृणुयादपि यः पठेत् विद्याधरपुरे सो ऽपि वसेत्कल्पायुतत्रयम् //
sārasvataṃ vrataṃ yastu śṛṇuyādapi yaḥ paṭhet vidyādharapure so 'pi vasetkalpāyutatrayam //
Whoever listens to, or even recites, the Sarasvata vow (Sārasvata-vrata), that person too dwells in the city of the Vidyādharas for three ayutas of kalpas.
This verse does not discuss pralaya directly; it is a phalaśruti (statement of results) promising a celestial post-mortem realm (Vidyādhara-pura) as the fruit of hearing/reciting the Sarasvata-vrata.
It frames a practical dharmic duty—śravaṇa (listening) and pāṭha (recitation) of a prescribed vow—as accessible merit-making for householders (and rulers alike), emphasizing that even participation through hearing grants spiritual reward.
The ritual significance is the Sarasvata-vrata itself and its phala (reward); no Vāstu or temple-building rule is stated, but the verse highlights the Purāṇic principle that correct vow-observance and recitation yield defined spiritual destinations.