B.G 10.12 and 13
Arjuna said:
You are the supreme Brahman, the supreme abode, the supreme purifier, the eternal, divine person, the primal god, the unborn, and the all-pervading one.
All the sages have declared you so, and so too has the divine sage Nārada, Asita, Devala, and Vyāsa; and now you yourself also say this to me.
Gīta Bhāshya 10.12 and 13
'Brahma' - completely full and perfect in all aspects; 'Paraṁ brahma' - Because it expands and causes all to expand; 'Paramam' - He who is the great Brahman; 'Prabhu' - he is the first cause; 'Vibhu' - as He became manifold;
The word 'brahma' means completely full and perfect in all aspects.
"Why is it called the supreme Brahman? Because it expands and causes all to expand."
- stated thus in the Vedic testimonial.
The words 'Bṛh', 'Bṛhi', and 'vṛddhau', i.e. growth or expansion, are declared as synonyms.
"The word 'paramam', i.e. the Supreme, is He who is the great Brahman."
- stated thus as well.
Because it (Brahman) existed in diverse forms, it is called 'Vibhuḥ'; so indeed, it is said in the Vāruṇa branch of the Veda:
“The first manifested form of the Lord is called 'Vibhu' and 'Prabhu'; called 'Vibhu' as He became manifold, called 'Prabhu' as he is the first cause.”
- stated thus.
"He desired, 'May I become many; may I create offspring'."
- thus is the scriptural declaration.