Mbh 1.2.16

“Then is recited the wonderful Parva called Drona full of incidents. First comes the installation in the command of the army of the great instructor in arms, Drona: then the vow made by that great master of weapons of seizing the wise Yudhishthira in battle to please Duryodhana; then the retreat of Arjuna from the field before the Sansaptakas, then the overthrow of Bhagadatta like to a second Indra in the field, with the elephant Supritika, by Arjuna; then the death of the hero Abhimanyu in his teens, alone and unsupported, at the hands of many Maharathas including Jayadratha; then after the death of Abhimanyu, the destruction by Arjuna, in battle of seven Akshauhinis of troops and then of Jayadratha; then the entry, by Bhima of mighty arms and by that foremost of warriors-in-chariot, Satyaki, into the Kaurava ranks impenetrable even to the gods, in search of Arjuna in obedience to the orders of Yudhishthira, and the destruction of the remnant of the Sansaptakas. In the Drona Parva, is the death of Alambusha, of Srutayus, of Jalasandha, of Shomadatta, of Virata, of the great warrior-in-chariot Drupada, of Ghatotkacha and others; in this Parva, Aswatthaman, excited beyond measure at the fall of his father in battle, discharged the terrible weapon Narayana. Then the glory of Rudra in connection with the burning (of the three cities). Then the arrival of Vyasa and recital by him of the glory of Krishna and Arjuna. This is the great seventh Parva of the Bharata in which all the heroic chiefs and princes mentioned were sent to their account. The number of sections in this is one hundred and seventy. The number of slokas as composed in the Drona Parva by Rishi Vyasa, the son of Parasara and the possessor of true knowledge after much meditation, is eight thousand, nine hundred and nine.