The unimaginable nature of God is elaborated in Veda by various statements

[dattaswami]

The unimaginable nature of God is elaborated in Veda by various statements
Aamnaaya Vistarat cha.

(The unimaginable nature of God is elaborated in Veda by various statements).

   Veda clearly elaborates the unimaginable nature of God through the following statements: Words cannot give knowledge of God (Yatovaachah, Na tatra vaak…).  Even mind cannot touch God (Apraapya Manasaa Saha).  Intelligence cannot reach God (Namedhayaa, Yo Buddheh Paratah..). You cannot understand God through logic (Naishaa Tarkena…, Atarkyah..).  Senses cannot grasp God (Nachakshushaa…, Aprameyah…, Atindriyam….).  All these statements have elaborated the concept of unimaginable nature of God by any means. 

Brahman is created by God

Brahma Yogat Vedaadishu Gitam Shrutam cha.

(The word Brahman is used in imaginable items like Veda through its root meaning i.e., greatest.  Such usage is found in Gita and its usage in other items is seen in Veda also.).

   In Gita it is said that Brahman is created by God (Brahmaakshara Samudbhavam).  Here Brahman cannot mean God.  It means the Veda, which is greatest among all the scriptures due to absence of additions and deletions, since Veda is protected by oral recitations from generations together.  The word Brahman is used in Veda to mean other greatest items like food (Annam Brahmeti…). Therefore, the word Brahman is not restricted to the unimaginable God and hence God is confused to be any greatest worldly item in its corresponding category.  For this reason only, the author would like to restrict the word Para Brahman to the unimaginable God only and avoid the confusion. 

Inability of sages to understand the context in using the word Brahman
Aarshaprakaranasaamarthyaabhavat Kalahah.

(The present confusion and split are due to the absence of ability of the sages to take the meaning of the word Brahman according to the context).
   The ancient sages were having the divine ability to take the correct meaning of the word Brahman as per the context. Therefore, there was no confusion in the case of sages and hence the word Brahman was used to mean both the God and other greatest worldly items.  According to the context, either God or the worldly item was perfectly selected by the sages in the Veda.  Hence, there was no necessity of using a separate word like Para Brahman for God.  But, today, the human beings are not having such divine ability due to fall in their standards.  Hence, there is a real need for restricting God by an isolated word i.e., Para Brahman.