Adhyāya 159 — Dāna–Dakṣiṇā, Āpaddharma Measures, and Prāyaścitta Classifications
न ते चालयितुं शक्या धर्मव्यापारकारिण: । न तेषां भिद्यते वृत्तं यत्पुरा साधुभि: कृतम्
na te cālayituṁ śakyā dharmavyāpārakāriṇaḥ | na teṣāṁ bhidyate vṛttaṁ yat pūrā sādhubhiḥ kṛtam ||
Bhishma said: Those who are engaged in the practice of dharma cannot be shaken from righteous action. Their established conduct does not break; they continue to follow the very code of good behavior that the virtuous of earlier times observed, and that noble discipline in them does not perish.
भीष्म उवाच
True practitioners of dharma are not easily swayed by temptation, fear, or persuasion; their moral conduct remains stable because it is grounded in time-tested sadācāra established by earlier virtuous people.
In the Shanti Parva’s instruction on righteous living, Bhishma is describing the character of dharmic persons: they remain devoted to dharma-practice and preserve the inherited standards of noble conduct without letting them deteriorate.