Book 10, Adhyāya 12: Aśvatthāmā’s Request for the Cakra and the Brahmaśiras Context
स संरम्भी दुरात्मा च चपल: क्रूर एव च । वेद चास्त्रं ब्रह्मशिरस्तस्माद् रक्ष्यो वृकोदर:
sa saṃrambhī durātmā ca capalaḥ krūra eva ca | veda cāstraṃ brahmaśirastasmād rakṣyo vṛkodaraḥ ||
वैशम्पायन बोले—वह क्रोध में उन्मत्त, दुष्टात्मा, चंचल और नितान्त क्रूर है। और उसे ‘ब्रह्मशिरस्’ नामक अस्त्र का भी ज्ञान है; इसलिए उससे वृकोदर (भीमसेन) की विशेष रक्षा करनी चाहिए।
वैशम्पायन उवाच
The verse warns that moral corruption combined with mastery of catastrophic weapons makes a person exceptionally dangerous; dharma in such a context requires vigilance and protective responsibility toward those at risk.
Vaiśampāyana characterizes a hostile figure as wrathful, wicked, fickle, and cruel, and notes his knowledge of the Brahmaśiras weapon; on that basis he urges that Bhīma (Vṛkodara) be guarded against him.