Adhyāya 166: Kṛtaghna-doṣa (कृतघ्नदोषः) — the fault of ingratitude and the limits of expiation
तया स काये निर्दग्धे मृत्युं वा प्राप्प शुद्धयति । लोकांश्व लभते विप्रो नान्न्यथा लभते हि सः
tayā sa kāye nirdagdhe mṛtyuṃ vā prāpya śuddhyati | lokāṃś ca labhate vipro nānyathā labhate hi saḥ ||
ভীষ্ম বললেন—সেই (উষ্ণ বারুণী) দ্বারা যদি তার দেহ দগ্ধ হয়, তবে—তাতে তার মৃত্যু হোক বা সে বেঁচে থাকুক—সে শুদ্ধ হয়। এমন শুদ্ধির পরেই সেই ব্রাহ্মণ শুদ্ধ লোক লাভ করে; নচেৎ সে তা লাভ করে না।
भीष्म उवाच
The verse teaches that grave transgressions require a corresponding expiation (prāyaścitta). Only through genuine purification—here described as a severe penance involving bodily burning or even death—can a brāhmaṇa regain eligibility for ‘pure worlds’; without purification, such spiritual attainment is denied.
In Śānti Parva, Bhīṣma is instructing Yudhiṣṭhira on dharma and expiations. Here he states a rule about purification after the sin of drinking liquor: if the offender drinks it heated so that the body is scorched (and whether he dies or survives), he is considered purified; only then can he attain higher realms.