Matsya Purana — Cosmography of Jambūdvīpa: Varṣas
एकाहाज्जायते युग्मं समं चैव विवर्धते समं रूपं च शीलं च समं चैव म्रियन्ति वै //
ekāhājjāyate yugmaṃ samaṃ caiva vivardhate samaṃ rūpaṃ ca śīlaṃ ca samaṃ caiva mriyanti vai //
A pair (of twins) is born on the very same day and grows in equal measure. Their form and disposition are alike, and indeed they also die at the same time.
It does not describe Pralaya directly; it highlights the fixed regularity of embodied life—birth, growth, and death—unfolding in patterned sameness, which complements the Purana’s broader view of cyclical time.
By stressing the inevitability and sameness of life’s stages, it supports ethical governance and household discipline: rulers and householders should act with dharma and foresight, knowing life’s course is finite and outcomes can be closely shared among kin.
No Vastu or ritual procedure is stated in this verse; its focus is biological and karmic parity (especially regarding twins), not temple-building or rites.