यस्य वीर्येण सहसा चत्वारो भुवि पाण्डवा:
yasya vīryeṇa sahasā catvāro bhuvi pāṇḍavāḥ
Sañjaya said: “By whose prowess, in a sudden surge of might, the four Pāṇḍava brothers on earth (were able to act with decisive force).”
संजय उवाच
The line foregrounds the ethical weight of vīrya (heroic power): decisive action in the world often depends on the strength and character of a central figure, implying that power should be aligned with dharma rather than mere impulse.
Sañjaya is describing events and attributing the Pāṇḍavas’ effective, forceful capability to the prowess of a particular person (implied by “whose”), setting up praise or explanation of that figure’s decisive influence.