The auditory Expression ‘AUM‘, as was the expression ‘Brahman‘, was a Mantric terms meant for Yagnic formalities before it took on conventional lingual meaning.
It is made-up of four elements. The beginning vowel ‘A’, the ending consonant ‘M’, and the middle ‘oo!’
They, between their stretch capture all of spoken sound and symbolically mark all ‘Expression’.
But the heart of the Mantram, the fourth element Turiya, is the unheard silence that complements the sonant expression itself. It translates literally as ‘The Immaculately Pure’.
Over time just as with ‘True Nothing’ getting calcified as ‘Being’ [See Posts], Turiya gets conceptualized and reified, assigned aspects and characteristics and ‘properties’, inscrutable rconnotations are imputed to ‘AUM’ and secret formulas devised to reveal them. I’ll cover it more detail in a later Post.