Use of words for Brahman
Brahman is not an object, is free from attributes and, therefore, beyond words and ideas. Up Sah 18.24 states that word or idea can refer to objects of knowledge and not to non-objects. Brahman is known and realized as the innermost self and the ultimate subject and is therefore not an object of knowledge. The same idea is reiterated in 18.28 which says that word can apply to ego which is possessed of species and not to Self which has no classification, i.e., swagata, sajAtatiya and vijAtiya. Self is devoid of any differentiation. The question is why are words used to describe It?
ShankarAchArya clarifies. Because of proximity with Self (Consciousness), the intellect is sentient and there is emergence of thoughts, ‘I’, the ego and ‘mine’. It is like a crystal appearing red in close proximity with red flower (18.27). 18.29-31 explain further. The word ‘I’ is applied to ego which is intellect with chidAbhAsa. The metaphor of fire and torch is apt. The action of burning is applied to the torch (with fire in it) though it is the fire which burns. Likewise, the word ‘I’ implying Existence, Consciousness, and Bliss describing the Self are applied to the ego having chidAbhAsa and appearing like It.
To sum up, the answer of the Q is like this. As Brahman is beyond word and idea, the Sruti ‘teaches’ It in an indirect way by applying the words describing Its nature to an object which appears similar to It. It is then silent as it were and expects the student to drop the dissimilarities which are mithya and establish the identity.
Concluded