Droṇa-parva Adhyāya 125: Duryodhana’s despair and vow after Jayadratha’s fall (जयद्रथवधे दुर्योधनविलापः)
त॑ प्रयान्तं नरश्रेष्ठं पुत्रो दःशासनस्तव
taṁ prayāntaṁ naraśreṣṭhaṁ putro daḥśāsanas tava
Sañjaya said: As that best of men was departing, your son Duḥśāsana (also) [went/acted in response].
संजय उवाच
The verse underscores how the actions of prominent warriors immediately provoke responses from others—especially in war—highlighting the chain of consequence and the ethical weight of following leaders into conflict.
Sañjaya reports to Dhṛtarāṣṭra that as a foremost warrior departs or advances, Dhṛtarāṣṭra’s son Duḥśāsana is involved in the ensuing movement or reaction, indicating Kaurava participation in the unfolding battle episode.