Skandapurana 6.3.1.24

6.3.1.24

ubhābhyāṃ yattu dṛṣṭaṃ hi tatpurāṇeṣu gīyate .
purāṇaṃ sarvaśāstrāṇāṃ prathamaṃ brahmaṇaḥ smṛtam .. 1.24 ..

and what is seen by both is sung in the Purāṇas. / The Purāṇa is remembered as the first of all sacred teachings from Brahmā. (1.24)