tan nah param punyam asamvrtartham
tat—therefore; nah—unto us; param—supreme; punyam—purifying; asamvrta-artham—as it is; akhyanam—narration; ati—very; adbhuta—wonderful; yoga-nistham—compact in bhakti-yoga; akhyahi—describe; ananta—the Unlimited; acarita—activities; upapannam—full of; pariksitam—spoken to Maharaja Pariksit; bhagavata—of the pure devotees; abhiramam—particularly very dear.
Thus please narrate to us the narrations of the Unlimited, for they are purifying and supreme. They were spoken to Maharaja Pariksit, and they are very dear to the pure devotees, being full of bhakti-yoga.
What was spoken to Maharaja Pariksit and what is very dear to the pure devotees is Srimad-Bhagavatam. Srimad-Bhagavatam is mainly full of the narrations of the activities of the Supreme Unlimited, and therefore it is the science of bhakti-yoga, or the devotional service of the Lord. Thus it is para, or supreme, because although it is enriched with all knowledge and religion, it is specifically enriched with the devotional service of the Lord.
Link to this page: https://prabhupadabooks.com/sb/1/18/17