Nirmaryāda-saṃgrāma-varṇana — The Unbounded Clash and Bhīṣma’s Rallying Presence
तस्माच्छास्त्र प्रमाणं ते कार्याकार्यव्यवस्थितौ । ज्ञात्वा शास्त्रविधानोक्त कर्म कर्तुमिहाहसि,इससे तेरे लिये इस कर्तव्य और अकर्तठव्यकी व्यवस्थामें शास्त्र ही प्रमाण है। ऐसा जानकर तू शास्त्रविधिसे नियत कर्म ही करनेयोग्य हैः
tasmāc chāstra-pramāṇaṁ te kāryākārya-vyavasthitau | jñātvā śāstra-vidhānoktaṁ karma kartum ihārhasi ||
Therefore, for you the authoritative standard in determining what ought to be done and what ought not to be done is the śāstra. Knowing the action that is enjoined by scriptural ordinance, you should perform that prescribed duty here—so that choice is guided by dharma rather than impulse or personal preference.
अजुन उवाच
When deciding between duty and non-duty (kārya and akārya), one should treat śāstra as the decisive authority; having understood what the injunctions prescribe, one should act accordingly.
In the midst of the war-context discourse, the speaker instructs the listener to resolve moral uncertainty by appealing to śāstric guidance and then to carry out the prescribed action as dharma demands.