Adhyāya 166: Kṛtaghna-doṣa (कृतघ्नदोषः) — the fault of ingratitude and the limits of expiation
यस्तु दूषयिता तस्या: शेषं प्राप्रोति पाप्मन: । ब्राह्मणानवगह्ठोह स्पृष्टवा गुरुतरं भवेत्
yastu dūṣayitā tasyāḥ śeṣaṃ prāpnoti pāpmanaḥ | brāhmaṇān avagahṭhoḥ spṛṣṭvā gurutaraṃ bhavet ||
Bhishma said: But the man who defames her becomes the recipient of the remaining portion of the sin. Moreover, in this world, one incurs a very grave fault by abusing brāhmaṇas or by pushing them aside with contempt.
भीष्म उवाच
Slander and contemptuous treatment of the virtuous—especially brāhmaṇas—carry heavy moral consequences; the defamer becomes liable for a significant share of the sin generated by such wrongdoing.
In Bhīṣma’s instruction on dharma in the Śānti Parva, he explains how sin is apportioned in acts involving dishonor and emphasizes that abusing or physically humiliating brāhmaṇas is a particularly grave transgression.