Yuga-Vibhāga and Kāla-Pramāṇa
Measures of Time and the Four Yugas
त्रेतादौ संहिता वेदाः केवला धर्मसेतवः / संरोधादायुषश्चैव वर्त्स्यन्ते द्वापरेषु वै
tretādau saṃhitā vedāḥ kevalā dharmasetavaḥ / saṃrodhādāyuṣaścaiva vartsyante dvāpareṣu vai
At the dawn of Tretā, the Vedas were only Saṃhitās, nothing but bridges of dharma; as lifespan contracted, they would endure in Dvāpara (in divided form).