Brahmā taught these Vedas to his sons, who were great sages among the brāhmaṇas and experts in the art of Vedic recitation. They in turn took the role of ācāryas and imparted the Vedas to their own sons.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
पुत्रानध्यापयत्तांस्तु ब्रह्मर्षीन् ब्रह्मकोविदान् । ते तु धर्मोपदेष्टारः स्वपुत्रेभ्यः समादिशन्
putrānadhyāpayattāṃstu brahmarṣīn brahmakovidān | te tu dharmopadeṣṭāraḥ svaputrebhyaḥ samādiśan
SB 12.6.45