Śānti-parva Adhyāya 3: Karṇa’s training under Rāma Jāmadagnya and the Bhārgava restriction on the Brahmāstra
स तस्योरुमथासाद्य बिभेद रुधिराशन: । न चैनमशकत् क्षेप्तुं हन्तुं वापि गुरोर्भयात्
sa tasyorum athāsādya bibheda rudhirāśanaḥ | na cainam aśakat kṣeptuṁ hantuṁ vāpi guror bhayāt ||
वह रक्तभोजी कीड़ा उसकी जाँघ तक पहुँचकर उसे छेदने लगा; पर गुरु के भय (और आदर) से कर्ण न तो उसे फेंक सका, न मार सका।
नारद उवाच
Even under extreme threat, the narrative highlights restraint governed by guru-reverence: the impulse to retaliate is checked by the ethical weight of one’s relationship to the teacher, showing how dharma can limit violence.
A fierce blood-eating being reaches the person’s thigh and wounds it, but the victim does not throw the attacker off or kill him, restrained by fear/awe of the guru—suggesting the attacker is connected to the teacher or the situation is bound by the guru’s authority.