the Petakopadesa and the Nettippakarana are considerably prior to the main Pali commentaries: they were probably composed in North India around the first century BCE and, because they were both known to Buddhaghosa, were reintroduced to Ceylon well before the fifth century CE, though not necessarily at the same time. Therefore they are invaluable documents for the study of the history of Pali exegesis and of the shift from the Nikaya worldview to the Abhidhamma framework.
The Petakopadesa thus appears to have survived from a time were the commentarial tradition was based on a less scholarly but rather pragmatic search for refining the teaching and study of the Dhamma.
