SB 12.7.8

purāṇa-lakṣaṇaṁ brahman
 brahmarṣibhir nirūpitam
śṛṇuṣva buddhim āśritya
 veda-śāstrānusārataḥ
Synonyms: 
purāṇa-lakṣaṇam — the characteristics of a Purāṇa; brahman — O brāhmaṇa, Śaunaka; brahma-ṛṣibhiḥ — by great learned brāhmaṇas; nirūpitam — ascertained; śṛṇuṣva — please hear; buddhim — intelligence; āśritya — resorting to; veda-śāstra — the Vedic scriptures; anusārataḥ — in accordance with.
Translation: 
O Śaunaka, please hear with attention the characteristics of a Purāṇa, which have been defined by the most eminent learned brāhmaṇas in accordance with Vedic literature.