SB 12.3.21

tadā kriyā-tapo-niṣṭhā
 nāti-hiṁsrā na lampaṭāḥ
trai-vargikās trayī-vṛddhā
 varṇā brahmottarā nṛpa
tadā — then (in the Tretā age); kriyā — to ritualistic ceremonies; tapaḥ — and to penances; niṣṭhāḥ — devoted; na ati-hiṁsrāḥ — not excessively violent; na lampaṭāḥ — not wantonly desiring sense gratification; trai-vargikāḥ — interested in the three principles of religiosity, economic development and sense gratification; trayī — by the three Vedas; vṛddhāḥ — made prosperous; varṇāḥ — the four classes of society; brahma-uttarāḥ — mostly brāhmaṇas; nṛpa — O King.
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.