Srimad Bhagavatam Canto 01, Chapter 03, Text 41

SB 1.3.41

tad idam grahayam asa
sutam atmavatam varam
sarva-vedetihasanam
saram saram samuddhrtam
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Sri Vyasadeva delivered it to his son, who is the most respected among the self-realized, after extracting the cream of all Vedic literatures and histories of the universe.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Men with a poor fund of knowledge only accept the history of the world from the time of Buddha, or since 600 B.C., and prior to this period all histories mentioned in the scriptures are calculated by them to be only imaginary stories. That is not a fact. All the stories mentioned in the Puranas and Mahabharata, etc., are actual histories, not only of this planet but also of millions of other planets within the universe. Sometimes the history of planets beyond this world appears to such men to be unbelievable. But they do not know that different planets are not equal in all respects and that therefore some of the historical facts derived from other planets do not correspond with the experience of this planet. Considering the different situation of different planets and also time and circumstances, there is nothing wonderful in the stories of the Puranas, nor are they imaginary. We should always remember the maxim that one man’s food is another man’s poison. We should not, therefore, reject the stories and histories of the Puranas as imaginary. The great rsis like Vyasa had no business putting some imaginary stories in their literatures.
 
In the Srimad-Bhagavatam historical facts selected from the histories of different planets have been depicted. It is therefore accepted by all the spiritual authorities as the Maha-purana. The special significance of these histories is that they are all connected with activities of the Lord in a different time and atmosphere. Srila Sukadeva Gosvami is the topmost personality of all the self-realized souls, and he accepted this as the subject of studies from his father, Vyasadeva. Srila Vyasadeva is the great authority, and the subject matter of Srimad-Bhagavatam being so important, he delivered the message first to his great son Srila Sukadeva Gosvami. It is compared to the cream of the milk. Vedic literature is like the Milk Ocean of knowledge. Cream or butter is the most palatable essence of milk, and so also is Srimad-Bhagavatam, for it contains all palatable, instructive and authentic versions of different activities of the Lord and His devotees. There is no gain, however, in accepting the message of Bhagavatam from the unbelievers, atheists and professional reciters who make a trade of Bhagavatam for the laymen. It was delivered to Srila Sukadeva Gosvami, and he had nothing to do with the Bhagavata business. He did not have to maintain family expenses by such trade. Srimad-Bhagavatam should therefore be received from the representative of Sukadeva, who must be in the renounced order of life without family encumbrance. Milk is undoubtedly very good and nourishing, but when it is touched by the mouth of a snake it is no longer nourishing; rather, it becomes a source of death. Similarly, those who are not strictly in the Vaisnava discipline should not make a business of this Bhagavatam and become a cause of spiritual death for so many hearers. In the Bhagavad-gita the Lord says that the purpose of all the Vedas is to know Him (Lord Krsna), and Srimad-Bhagavatam is Lord Sri Krsna Himself in the form of recorded knowledge. Therefore, it is the cream of all the Vedas, and it contains all historical facts of all times in relation with Sri Krsna. It is factually the essence of all histories.
 
Srimad Bhagavatam Canto 01, Chapter 03, Text 40
Srimad Bhagavatam Canto 01, Chapter 03, Text 42