Srimad-Bhagavatam: Canto 12 - Chapter 1 - Verse 41
Sanskrit:
पुराणसंहितामेतामृषिर्नारायणोऽव्यय: ।नारदाय पुरा प्राह कृष्णद्वैपायनाय स: ॥ ४१ ॥
ITRANS:
purāṇa-saṁhitām etāmṛṣir nārāyaṇo ’vyayaḥnāradāya purā prāhakṛṣṇa-dvaipāyanāya saḥ
Translation:
Long ago this essential anthology of all the Purāṇas was spoken by the infallible Lord Nara-Nārāyaṇa Ṛṣi to Nārada, who then repeated it to Kṛṣṇa Dvaipāyana Vedavyāsa.