To the next stage, in which the epic, handed down by rhapsodists, swelled to a length of about 20,000 çlokas, belongs the representation of the victorious Pāṇḍus in a favourable light, and the introduction on a level with Brahmā of the two other great gods, Çiva, and especially Vishṇu, of whom Kṛishṇa appears as an incarnation.
We gather from the account of Megasthenes that about 300 B.C., these two gods were already prominent, and the people were divided into Çivaites and Vishnuites. Moreover, the Yavanas or Greeks are mentioned in the Mahābhārata as allies of the Kurus, and even the Çakas (Scythians) and Pahlavas (Parthians) are named along with them; Hindu temples are also referred to as well as Buddhist relic mounds. Thus an extension of the original epic must have taken place after 300 B.C. and by the beginning of our era.
The Brahmans knew how to utilise the great influence of the old epic tradition by gradually incorporating didactic matter calculated to impress upon the people, and especially on kings, the doctrines of the priestly caste. It thus at last assumed the character of a vast treatise on duty (dharma), in which the divine origin and immutability of Brahman institutions, the eternity of the caste system, and the subordination of all to the priests, are laid down. When the Mahābhārata attributes its origin to Vyāsa, it implies a belief in a final redaction, for the name simply means "Arranger." Dahlmann has recently put forward the theory that the great epic was a didactic work from the very outset; this view, however, appears to be quite irreconcilable with the data of the poem, and is not likely to find any support among scholars.
