Seeing Yudhishthira afflict your troops Drona, urged on by your son surrounded him (i.e. Yudhishthira) with arrows.
सैन्यानि द्रावयन्तं तं द्रोणो दृष्ट्वा युधिष्ठिरम्। चोदितस्तव पुत्रेण सायकैरभ्यवाकिरत्॥