Srimad Bhagavatam Canto 12, Chapter 13, Text 03

SB 12.13.3

purana-sankhya-sambhutim
 asya vacya-prayojane
danam danasya mahatmyam
 pathades ca nibodhata
 
Translation: 
 
Now please hear a summation of the verse length of each of the Puranas. Then hear of the prime subject and purpose of this Bhagavata Purana, the proper method of giving it as a gift, the glories of such gift-giving, and finally the glories of hearing and chanting this literature.
 
Purport: 
 
Srimad-Bhagavatam is the best of all Puranas. Srila Visvanatha Cakravarti Thakura explains that the other Puranas will now be mentioned just as the assistants of a king are mentioned in connection with his glorification.
Srimad Bhagavatam Canto 12, Chapter 13, Text 02
Srimad Bhagavatam Canto 12, Chapter 13, Text 04-09