Who first presented the concept of Brahman and one what basis, please? Did one investigate into it, please?
Regards
I think it is a deep question. I will try to answer as per my understanding.
Rig Veda has a verse regarding this.
Rig Veda
1-10-181 1. VASIstHA mastered the Rathantara, took it from radiant Dhātar, Savitar, and Visnu,
portion of fourfold oblation, known by the names of Saprathas and Prathas.
2. These sages found what lay remote and hidden, the sacrifice's loftiest secret essence.
From radiant Dhātar, Savitar, and Visnu, from Agni, Bharadvāja brought the Brhat.
3 They found with mental eyes the earliest Yajus, a pathway to the Gods, that had descended.
From radiant Dhātar, Savitar, and Visnu, from Sūrya did these sages bring the Gharma.
...
Primarily it is
rsi Vasista, one of the seven
rsis, who is the conveyor of
Rig Veda to sages (another rsi is
Bharadvaja) as
Sruti-- that which is heard in meditation.
Brahman is said to be intrinsically of the nature of Existence/Truth-Consciousness-Bliss. It is the lordly powers of
Brahman, symbolised by the lordly deities:
Dhātar, Savitar, and Visnu, that transmit the
Rig to
rsi Vasista.
The
rsis are the eternal-timeless workers in all of us who enable functioning of mind-senses. For example,
rsi Vasista is said to preside over our hearing. Probably, therefore, his name comes first in respect of the Vedas.
Brahman is Truth-Consciousness. But without the timeless-eternal
Ishwara, there would be no
mAyA creation, no guardian teacher and no knowledge of Brahman.
Ishwara (Lord) is an integral aspect of
Brahman. Only egotist fools assert the reality of self as ego (body-mind-intellect) but deny the
Ishwara -- the very root of the ego.
...