Ādi-parva Adhyāya 132 — Duryodhana’s Instructions to Purocana at Vāraṇāvata
Lākṣāgṛha Planning
राजपुत्रास्तथा चान्ये समेत्य भरतर्षभ । अभिजममुस्ततो द्रोणमस्त्रार्थे द्विजसत्तमम्,भरतश्रेष्ठ] उस समय दूसरे-दूसरे राजकुमार भी अस्त्रविद्याकी शिक्षा लेनेके लिये द्विजश्रेष्ठ द्रोणके पास आने लगे
rājaputrās tathā cānye sametya bharatarṣabha | abhijagmur tato droṇam astrārthe dvijasattamam ||
Vaiśampāyana said: “O bull among the Bharatas, then other princes as well gathered together and went to Droṇa, the foremost of Brahmins, seeking instruction in the science of weapons.”
वैशम्पायन उवाच
Martial power is to be acquired through disciplined study under a qualified guru; legitimate training and restraint are implied prerequisites for righteous kingship and the proper exercise of kṣatriya force.
After the main royal students have begun their training, additional princes assemble and come to Droṇa to learn astravidyā (the science of weapons), expanding the circle of disciples around the famed teacher.