Those Indra-like ones who were kept confined in the cave of the mountain are none less then the five sons of Pandu, possessing great prowess. And the Pandava Savyasachi (Arjuna) is a portion of (the present) Indra.
स्तस्यां दर्यां पर्वतस्योत्तरस्य। इहैव ते पाण्डवा वीर्यवन्तः शक्रस्यांशः पाण्डवः सव्यसाची॥