Brāhmaṇa-vandana: Criteria for Veneration, Disciplined Speech, and Protective Kingship (अनुशासनपर्व, अध्याय ८)
ऋजून् सतः सत्यशीलान् सर्वभूतहिते रतान् । आशीविषानिव क्रुद्धान् द्विजान् परिचरेत् सदा
ṛjūn sataḥ satyaśīlān sarvabhūtahite ratān | āśīviṣān iva kruddhān dvijān paricaret sadā ||
Bhīṣma said: One should always attend upon and serve the twice-born who are straightforward, virtuous, devoted to truth, and engaged in the welfare of all beings—yet who, when angered, are like venomous serpents.
भीष्म उवाच
Maintain constant respect and service toward upright, truth-committed, universally benevolent dvijas; their spiritual and social power is to be treated with caution, since their anger can be as dangerous as a venomous snake.
In Bhīṣma’s instruction on dharma (Anuśāsana Parva), he advises the listener on proper conduct toward Brahmins and other dvijas, praising their virtues while warning that provoking their wrath brings grave consequences.