Bhagavad Gita 18.42
शमो दमस्तप: शौचं कांतिरर्जवमेव च |
ज्ञानं विज्ञानमास्तिक्यं ब्रह्मकर्म स्वभावजम्
Translation
Tranquility, restraint, austerity, purity, patience, integrity, knowledge, wisdom, and belief in a hereafter—these are the intrinsic qualities of work for Brahmins.