Chapter XVIII · Śloka 42
शमो दमस्तपः शौचं क्षान्तिरार्जवमेव च |
ज्ञानं विज्ञानमास्तिक्यं ब्रह्मकर्म स्वभावजम् ||
śamo damas tapaḥ śaucaṃ kṣāntir ārjavam eva ca |
jñānaṃ vijñānam āstikyaṃ brahma-karma svabhāva-jam ||
Serenity, self-control, austerity, purity, tolerance, uprightness, knowledge, realized wisdom, and belief in a higher reality — these are the duties of a brāhmaṇa, born of his own nature.
The brāhmaṇa's dharma is an inner discipline: the nine qualities listed are all attributes of consciousness itself. The brāhmaṇa is constituted, in the deepest sense, by the direction of their entire being toward knowledge and its living expression.