Matsya Purana — Measures of Time: Caturyuga Computation
हृष्टपुष्टा जनाः सर्वे अरोगाः पूर्णमानसाः एको वेदश्चतुष्पादस् त्रेतायां तु विधिः स्मृतः त्रीणि वर्षसहस्राणि जीवन्ते तत्र ताः प्रजाः //
hṛṣṭapuṣṭā janāḥ sarve arogāḥ pūrṇamānasāḥ eko vedaścatuṣpādas tretāyāṃ tu vidhiḥ smṛtaḥ trīṇi varṣasahasrāṇi jīvante tatra tāḥ prajāḥ //
In the Tretā Yuga, all people are cheerful and well-nourished, free from disease and of fulfilled minds. The Veda is one, yet it stands on four feet (fully established); such is the ordained order remembered for the Tretā. The beings there live for three thousand years.
This verse does not describe Pralaya; it outlines the flourishing conditions of the Tretā Yuga—health, contentment, stable Vedic order, and long lifespan—indicating a phase of cosmic stability rather than dissolution.
By portraying a society that is healthy and mentally fulfilled under an established Vedic vidhi, it implies that rulers and householders should uphold Vedic order (dharma and ritual discipline) to sustain prosperity, public health, and social harmony.
The direct significance is ritual: “vidhi” and the Veda being “catuṣpāda” indicate a well-established, complete sacrificial and dharmic system in Tretā Yuga; no explicit Vāstu or temple-building rule is stated in this verse.