Matsya Purana — Cosmography of Śākadvīpa and Successive Dvīpas: Mountains
सर्वतः सुमहान्द्वीपश् चन्द्रवत्परिवेष्टितः विस्तारान्मण्डलाच्चैव क्षीरोदाद्द्विगुणो मतः //
sarvataḥ sumahāndvīpaś candravatpariveṣṭitaḥ vistārānmaṇḍalāccaiva kṣīrodāddviguṇo mataḥ //
On every side there is a very great continent, encircled like the moon by a surrounding ring; in both its breadth and its circular extent, it is understood to be twice the measure of the Ocean of Milk (Kṣīroda).
It does not describe Pralaya directly; it gives a structural, measured picture of the ordered cosmos—continents and oceans arranged in rings—implying a stable cosmic design that later texts contrast with dissolution.
Indirectly, it supports the Purāṇic ideal that rulers and householders should align ritual life (yajña, dāna, tīrtha) with a well-ordered cosmos; sacred geography frames pilgrimage, calendrics, and merit-making rather than prescribing political duties here.
Architecturally, it models the idea of concentric planning (maṇḍala-like ring structure) often echoed in temple/town symbolism; ritually, it situates Kṣīroda as a cosmic reference-point used in Purāṇic visualization and cosmological contemplation.