Matsya Purana — Description of Gomedaka and Puṣkara Dvīpas; the Lokāloka Boundary; Ocean Tide...
योजनानां सहस्राणि सार्धं पञ्चाशदुच्छ्रितः तस्य पुत्रो महावीतः पश्चिमार्धस्य रक्षिता //
yojanānāṃ sahasrāṇi sārdhaṃ pañcāśaducchritaḥ tasya putro mahāvītaḥ paścimārdhasya rakṣitā //
He rose to a height of one thousand yojanas and fifty more; his son, Mahāvīta, became the protector of the western region.
This verse does not discuss pralaya; it belongs to a genealogical/regional account describing a ruler’s extraordinary stature and the appointment of a guardian of the western region.
By calling Mahāvīta the “protector of the western region,” the verse highlights the kingly duty of rakṣaṇa—guarding territory and maintaining order as a core function of righteous rule.
No direct Vāstu or ritual procedure is stated; the only technical element is the use of yojana as a traditional measure, which can contextualize Purāṇic descriptions of scale.