My dear King, Brahmā, the firstborn, on being questioned by Nārada, exactly apprised him on this subject as it had been directly spoken by the Lord to His own son, who was impregnated with Vedic knowledge from his very birth.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
एतदेवात्मभू राजन् नारदाय विपृच्छते । वेदगर्भोऽभ्यधात्साक्षाद्यदाह हरिरात्मनः
etadevātmabhū rājan nāradāya vipṛcchate | vedagarbho'bhyadhātsākṣādyadāha harirātmanaḥ
SB 2.4.25