As Droṇa was watching the Kaurava-s and the Pāṇḍava-s playing, Yudhiṣṭhira’s ring slipped and fell into a deep well. When the boys had given up any hope of retrieving it, Droṇa instructed his son Aśvatthāma to remove it. Aśvatthāma aimed an arrow at the ring. It found its mark. He then aimed another arrow at the fin of that arrow. Thus, building a chain of arrows, Aśvatthāma removed the ring out.

The Kaurava-s and the Pāṇḍava-s were impressed by this feat. They narrated this incident to Bhīṣma and begged him to convince that Brāhmaṇa to be their Guru. Bhīṣma met Droṇa and paid him homage with generous gifts that made Droṇa a rich man. On a suitable day, Bhīṣma handed over the Kaurava-s and the Pāṇḍava-s to Droṇa to be instructed in the art of the use of weapons. A huge arena was created for this purpose. Thus the Kaurava-s and Pāṇḍava-s began their studies under Droṇa.

Karṇa, who was hitherto studying the use of weapons under Paraśurāma returned to Hastināpura after completing his studies. There he met with Duryodhana, who introduced him to Droṇa. Since that day, the friendship between Duryodhana and Karṇa grew. They became inseparable.

As days passed all the princes became adept at the use of various weapons. Bhīma and Duryodhana became experts in the art of wielding the Gadāyudha (Mace), while Karṇa and Arjuna excelled in the use of the Dhanuśa and Bāṇa (Bows and arrows). Among all the students, Arjuna was the one who became very close to Droṇa for his dedication and his skill in the use of weapons.

Audio Link: https://archive.org/download/kumaravyasa-bharata-recitation/Parva-01-Adiparva-006-Sandhi-Part-03-of-03.mp3