Garbhodakasayi Visnu, Lord Brahma and Narada

"Lord Brahma, the spiritual master of Narada Muni, is the first living entity within the universe. He received all Vedic knowledge from the Supreme Lord Krsna, who directly imparted the transcendental knowledge from within his heart."

"In the beginning of the creation, Brahma is born first without any father and mother because before Brahma there were no other living beings. Brahma is born from the lotus which grows from the abdomen of the Garbhodakasayi Visnu, and therefore he is known as Aja. This Brahma, or Aja, is also a living being, part and parcel of the Lord, but being the most pious devotee of the Lord, Brahma is inspired by the Lord to create, subsequent to the main creation by the Lord, through the agency of material nature. ....The Vedic knowledge was therefore first impregnated within Brahma, and it appears that Brahma distributed the Vedic knowledge. Brahma is undoubtedly the speaker of the Vedic knowledge, but actually he was inspired by the Lord to receive such transcendental knowledge, as it directly descends from the Lord. The Vedas are therefore called apauruseya, or not imparted by any created being. Before the creation the Lord was there (narayanah paro 'vyaktat), and therefore the words spoken by the Lord are vibrations of transcendental sound. There is a gulf of difference between the two qualities of sound, namely prakrta and aprakrta. The physicist can deal only with the prakrta sound, or sound vibrated in the material sky, and therefore we must know that the Vedic sounds recorded in symbolic expressions cannot be understood by anyone within the universe unless and until one is inspired by the vibration of supernatural (aprakrta) sound, which descends in the chain of disciplic succession from the Lord to Brahma, from Brahma to Narada, from Narada to Vyasa and so on. No mundane scholar can translate or reveal the true import of the Vedic mantras (hymns). They cannot be understood unless one is inspired or initiated by the authorized spiritual master. The original spiritual master is the Lord Himself, and the succession comes down through the sources of parampara, as clearly stated in the Fourth Chapter of the Bhagavad-gita. So unless one receives the transcendental knowledge from the authorized parampara, one should be considered useless (viphala matah), even though one may be greatly qualified in the mundane advancements of arts or science."

Srimad-Bhagavatam 2:4:22 Purport

"The disciplic succession holds that the Vedas were uttered by Lord Krsna to Brahma, by Brahma to Narada, and by Narada to Vyasadeva, and then by Vyasadeva to Sukadeva Gosvami and so on. So there is no difference between the versions of all the authorities. The truth is eternal, and as such there cannot be any new opinion about the truth. That is the way of knowing the knowledge contained in the Vedas. It is not a thing to be understood by one's erudite scholarship or by the fashionable interpretations of mundane scholars. There is nothing to be added and nothing to be subtracted, because the truth is the truth."

Srimad-Bhagavatam 2:2:32 Purport

Lord Brahma and Narada (left); Narada and Vyasa (right)

"It is stated in the beginning of Srimad-Bhagavatam, tene brahma hrda. The sound of Brahman, or Veda, was first impregnated into the heart of Brahma, the original learned man (adi-kavaye). How did he become learned? Whenever there is learning, there must be a speaker and the process of hearing. But Brahma was the first created being. Who spoke to him? Since no one was there, who was the spiritual master to give knowledge? He was the only living creature; therefore the Vedic knowledge was imparted within his heart by the Supreme Personality of Godhead, who is seated within everyone as Paramatma. Vedic knowledge is understood to be spoken by the Supreme Lord, and therefore it is free from the defects of material understanding. Material understanding is defective. If we hear something from a conditioned soul, it is full of defects. All material and mundane information is tainted by illusion, error, cheating and imperfection of the senses. Because Vedic knowledge was imparted by the Supreme Lord, who is transcendental to material creation, it is perfect. If we receive that Vedic knowledge from Brahma in disciplic succession, then we receive perfect knowledge."

Srimad-Bhagavatam 3:26:33 Purport

Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.