Matsya Purana — The Observance of Viśoka-Dvādaśī: A Lakṣmī–Viṣṇu Vow for Sorrow-Removal and P...
चतुरस्रं समन्ताच्च रत्निमात्रमुदक्प्लवम् श्लक्ष्णं हृद्यं च परितो वप्रत्रयसमावृतम् //
caturasraṃ samantācca ratnimātramudakplavam ślakṣṇaṃ hṛdyaṃ ca parito vapratrayasamāvṛtam //
Let it be square on all sides, with a water-slope for drainage of one ratni; smooth and pleasing to the eye, and enclosed all around by three ramparts (earthen embankments).
This verse is not about Pralaya; it gives practical Vastu guidance—shape, drainage slope, surface finish, and defensive enclosure—showing how order and stability are established in human settlements.
For a king, it supports rajadharma through safe, well-drained, fortified civic planning; for householders/builders, it prescribes a clean, stable, aesthetically proper construction standard that prevents water damage and disorder.
Architecturally, it mandates a square plan, a defined drainage fall of one ratni, a smooth finish, and triple ramparts—key Vastu principles for durability, sanitation, and protection in settlement or precinct design.