Matsya Purana — Cosmography of Jambūdvīpa: Varṣas
अवगाह्य ह्युभयतः समुद्रौ पूर्वपश्चिमौ हिमप्रायश्च हिमवान् हेमकूटश्च हेमवान् //
avagāhya hyubhayataḥ samudrau pūrvapaścimau himaprāyaśca himavān hemakūṭaśca hemavān //
Plunging down on both sides into the eastern and western oceans, there lie the snow-laden Himavān, and also Hemakūṭa, together with Hemavān.
This verse is not about Pralaya; it belongs to cosmographical narration, describing how major mountain ranges are situated with respect to the eastern and western oceans.
Indirectly, it supports Purāṇic dharma by mapping the sacred world—knowledge of tīrthas, regions, and boundaries that a king protects and a householder reveres through pilgrimage and ritual geography.
No direct Vāstu or temple-rule is stated; the practical ritual takeaway is the Purāṇic emphasis on sacred geography (mountains and oceans) that underlies tīrtha-mahātmyas and region-based rites.