Matsya Purana — Solar–Lunar Motions
तथा शतसहस्राणाम् एकोननवतिं पुनः पञ्चाशच्च सहस्राणि पृथिव्यर्धस्य विस्तरः //
tathā śatasahasrāṇām ekonanavatiṃ punaḥ pañcāśacca sahasrāṇi pṛthivyardhasya vistaraḥ //
Likewise, the breadth (extent) of half of the earth is said to be ninety-nine hundred-thousands, and again fifty thousand (yojanas).
This verse is not about Pralaya; it belongs to cosmography, giving a numerical measure for the breadth/extent of half the earth in traditional large units (commonly understood as yojanas).
Indirectly, such cosmographical measures support the Purāṇic worldview used in royal administration (mapping realms, pilgrimage circuits, boundaries) and in householder practice (understanding sacred geography tied to tīrthas and ritual orientation).
The verse provides a scale-based conception of space; Vāstu and temple planning texts often rely on standardized measures, and Purāṇic cosmography supplies the sacred macro-scale framework that mirrors micro-scale planning (mandala, orientation, and proportional thinking).