Step 1: Understanding the Concept:
The word 'Purana' literally means "that which is old" (Pura nava bhavati). However, in a technical theological sense, the Puranas are viewed as the historical and cosmological records of different 'Kalpas' (aeons of cosmic time). A Kalpa is a day in the life of Brahma, and it is believed that different Puranas were revealed or took place in different Kalpas. This specific verse defines the nature of Puranic literature as the repository of ancient cosmic history.
Step 2: Detailed Explanation:
The statement "Puratanasya kalpasya puranani vidurbudhah" is found in the Matsya Purana. This text is one of the oldest and most authentic of the eighteen Mahapuranas. In its introductory and concluding sections, the Matsya Purana explains the origin of the Puranas. It states that before the Vedas were divided by Vyasa, there was a single primordial Purana consisting of a hundred crore (one billion) verses. This primordial Purana contained the history of the universe as it unfolded in ancient Kalpas.
The verse signifies that the Puranas are not mere fiction; they are the accounts of how the world was created, sustained, and dissolved in previous cycles of time. According to the Matsya Purana, the wise (Budhah) understand that the core purpose of these texts is to preserve the 'Kalpa-vrittanta' (the chronicles of time).
Why this is significant in the Matsya Purana:
1. The Matsya Purana provides the list of all 18 Puranas and their respective verse counts.
2. It links specific Puranas to specific Gunas (Sattva, Rajas, Tamas) and specific Kalpas (e.g., the Matsya Purana itself is associated with the 'Shveta-varaha Kalpa').
While the Vayu Purana (Option A) also provides similar definitions of 'Purana', and the Varaha and Padma Puranas contain vast mythological lore, the specific phrasing regarding the wise knowing Puranas as records of ancient Kalpas is a hallmark of the Matsya Purana's definition of the genre. This definition reinforces the status of Puranas as the 'Itihasa-Purana' complex, which completes and supplements the Vedas.
Step 4: Final Answer:
This statement is found in the Matsya Purana.