Matsya Purana — Paurava Genealogy
कृतयुगप्रमाणं च त्रेताद्वापरयोस्तथा कलियुगप्रमाणं च युगदोषं युगक्षयम् //
kṛtayugapramāṇaṃ ca tretādvāparayostathā kaliyugapramāṇaṃ ca yugadoṣaṃ yugakṣayam //
“(I shall explain) the measure of the Kṛta Yuga, and likewise of the Tretā and Dvāpara; also the measure of the Kali Yuga—together with the defects of each age and the waning (decline) of the yugas.”
It frames cosmic time as cyclical: each yuga has a defined measure and a progressive “decline” (kṣaya). This yuga-wise degeneration is a key backdrop for larger cycles that culminate in periodic dissolution (pralaya), even though pralaya is not described directly in this single verse.
By announcing “yuga-doṣa” (age-specific defects), the text implies that dharma and governance must be calibrated to the times—kings and householders should uphold conduct appropriate to the prevailing yuga, countering its characteristic moral weaknesses (especially in Kali).
No direct Vāstu or ritual procedure is stated; the relevance is contextual: yuga-based decline often determines which rites, standards, and allowable practices are emphasized or simplified in later ages, a principle used across Purāṇic ritual guidance.