At very first, Brahma (universe) was born among the gods, who is the doer of the whole world and the protector of the people; He narrated to his eldest son Atharva that Brahma-vidya in which all the Vidyas have prestige.
The knowledge of Brahma which was told by Brahma to Atharva in ancient times, was told by Atharva to Angir. Angir did to Bhardwaj Satyavah & Bhardwaj narrated both Para and Apara Vidyas (knowledge) to Angiras.
Mahashaladhipati Shaunaka, duly came to Angiras in the form of a disciple and asked himː "O Lord! What is it that after knowing which all this is known?
Angiras said to them: There are two types of knowledge that are worth knowing, about which the Brahmavid-knowledgeable says, Para and Apara.
Apara's are Rigveda, Yajurveda, Samaveda, Atharvaveda, Kalpa (aeon), Grammar, Nirukta (unoccupied), Verses and Astrology. And Para Vidya is that which gives knowledge of 'Akshar Tattva' (Sacred Syllables).
'That' which is invisible, unattainable, relationless (Agotra). It is formless, without eyes and hearing, which is without hands and feet, eternal, omnipresent, all-pervading, all-pervading, infinitesimal, imperishable, which is the origin of all living beings, the wise see him everywhere.
Just as a spider creates its web and wraps it in itself, just as medicines are produced on earth, just as the hair of the body and head of a living human being grows, in the same way, from the 'Akshara Tatva' That's all is originated.
'Brahman' is increased by penance, then 'from it' 'food' is generated. From 'food' life, mind, truth and worlds, and immortality in action.
The one who is 'all-knowing', 'he' whose penance is enlightened, 'from him' this 'Brahman', this 'name', 'form' and 'food' are generated.