Bhuman literally means infinite and abundance and its experience is mentioned in the Chandogya Upanishad.
Chandogya Upanishad defines the infinite as that experience
of fullness after which one does not see, hear or understand anything as
different from oneself. The experience of duality being finite and transient, a
knowledge of the infinite leads to self-realization. It is realization of
identity in totality, a universalization of self.
The last three chapters (sixth, seventh and eighth) of Chandogya
Upanishad deal with Brahman. The sixth is known as sadvidya and is in the form
of a dialogue between Uddalaka and Svetaketu, the father and son. This discussion
leads to the enunciation of the doctrine ‘tat tvam asi’ (Thou art that). This
chapter deals with existence as an essential constituent of the concept of
Brahman. Omniscience and bliss are also essential constituents of this concept.
The essential nature of Brahman is Infinite.
Narada, in spite of being a divine seer, could not get out
of sorrow and misery. So he approached sage Sanatkumara, also known as Skanda,
to teach him atman as he had heard from great people that a knower of atman
alone could overcome sorrow. Like a good teacher, Sanatkumara asked him what he
had learnt till then and Narada gave a long list of subjects known to him.
Sanatkumara told him that what Narada had learnt were mere
namas (words) and not their meaning. He was asked to meditate on vak (speech),
manas (mind), samkalpa (will), cittam (thought), dhyanam (meditation), vijnanam
(comprehension), balam (power), annam (objects), apas (water), tejas (fire),
akasha (space), samaranam (memory), asha (hope), pranah (vitality), and satya
(truth).
Understanding vijnana (comprehension), mati (contemplation),
shraddha (faith), Nishtha (steadfast activity), kriti (action) and sukha (joy),
the last six being the accessories to bhuman.
After teaching Narada, Sanatkumara told him that the infinite
is based on Ananda (joy). It is rooted in itself. A self-realized soul becomes
svarat, kamachara (independent). The joy or bliss consists only in bhuman
(infinitude) and not in finitude. Individuation leads to pain and suffering.
Universalization is joy. Sanatkumara completes the instruction by stressing the
importance of purity in food, which alone can lead to purity of mind, conduct
and memory.
This instruction is variously called bhuma vidya, Narada
vidya or Sanat Kumara Narada Samvada.