Shloka 4.30.82
शरत्प्रवेशे रामविलापः तथा सुग्रीवप्रमादे लक्ष्मणप्रेषणम् (Autumn’s Onset: Rama’s Lament and Lakshmana Sent to Sugriva)
एक एव रणे वाली शरेण निहतो मया।त्वां तु सत्यादतिक्रान्तं हनिष्यामि सबान्धवम्।।
eka eva raṇe vālī śareṇa nihato mayā |
tvāṃ tu satyād atikrāntaṃ haniṣyāmi sabāndhavam ||
Vālī was struck down by me in battle with a single arrow. But you—if you have crossed beyond truth—I will destroy along with your kinsmen.
'Vali was killed by me in the battle with a single arrow while I shall kill you now along with your near and dear ones since you have deviated from the truth.'
Satya is treated as the boundary of rightful conduct; violating truth (promise/pledge) invites legitimate punishment under a ruler’s duty to uphold dharma.
Rāma compares his earlier slaying of Vālī to the potential punishment awaiting Sugrīva if he betrays the pledged mission to search for Sītā.
Rāma’s role as a dharma-enforcer—firmness and impartiality in ensuring that vows are not treated lightly.