Droṇa-parva Adhyāya 125: Duryodhana’s despair and vow after Jayadratha’s fall (जयद्रथवधे दुर्योधनविलापः)
भीमसेनेन तु वध: सुतानां तव भारत । प्रतिज्ञात: सभामध्ये सर्वेषामेव संयुगे
bhīmasenena tu vadhaḥ sutānāṃ tava bhārata | pratijñātaḥ sabhāmadhye sarveṣām eva saṃyuge ||
Sañjaya said: O Bhārata (Dhṛtarāṣṭra), the slaying of your sons by Bhīmasena had been vowed in the royal assembly, in the presence of all; and that vow was to be fulfilled in battle.
संजय उवाच
A publicly made vow (pratijñā), especially in a royal assembly, carries moral weight and social accountability; in the Mahābhārata’s war-ethic, such oaths become binding forces that drive action and its consequences, even when the outcome is tragic.
Sañjaya reminds Dhṛtarāṣṭra that Bhīma had earlier vowed, before all in the court, to slay Dhṛtarāṣṭra’s sons; the verse frames the ongoing killings in the war as the fulfillment of that earlier, publicly witnessed pledge.