Bhagavad Gita 18.42

18.42 Serenity, self-restraint, austerity, purity, forgiveness and also uprightness, knowledge, realisation and belief in God are the duties of the Brahmanas, born of (their own) nature.

Peacefulness, self-control, austerity, purity, tolerance, honesty, knowledge, wisdom and religiousness – these are the natural qualities by which the brāhmaṇas work.