Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 21
Sanskrit:
तदा क्रियातपोनिष्ठा नातिहिंस्रा न लम्पटा: ।त्रैवर्गिकास्त्रयीवृद्धा वर्णा ब्रह्मोत्तरा नृप ॥ २१ ॥
ITRANS:
tadā kriyā-tapo-niṣṭhānāti-hiṁsrā na lampaṭāḥtrai-vargikās trayī-vṛddhāvarṇā brahmottarā nṛpa
Translation:
In the Tretā age people are devoted to ritual performances and severe austerities. They are not excessively violent or very lusty after sensual pleasure. Their interest lies primarily in religiosity, economic development and regulated sense gratification, and they achieve prosperity by following the prescriptions of the three Vedas. Although in this age society evolves into four separate classes, O King, most people are brāhmaṇas.