Each book in the Vedas has one or a few verses that bring the conclusion of the book. That's the paribhasa-sutra. All other verses must be studied in the context of this verse to understand the text.
The Paribhasa-sutra of the Srimad Bhagavatam
Each book in the Vedas has one or a few verses that bring the conclusion of the book. That's the paribhasa-sutra. All other verses must be studied in the context of this verse to understand the text.