Arjuna said: You are the supreme Reality, the supreme Abode, the pure and Ultimate, eternal Puruṣa, resplendent, premier of gods, unborn and all-pervading.
The scene changes, obviously, after hearing Krishna speak of himself as the supreme Self, God being but its synonym. Arjuna is now a devotee. A new humility and fervour, curiosity and earnestness has overtaken Arjuna. He pours forth whatever comes to his heart, without hiding what he feels about his Krishna. Before one’s Guru, truly everything else becomes secondary, a point our scriptures emphasize repeatedly.
Sadguru becomes the supreme Lord for the true śishya. Feeling the awesome fervour of a śishya in full, Arjuna addresses Krishna as Brahman, the supreme Reality, a fact Krishna already disclosed (2.12). Many other descriptions also flow from Arjuna’s heart, all of which refer to the Supreme. The Self in everyone is all these, as Krishna has been revealing throughout!