yat tvayoktam vacas tena
moho ’yam vigato mama
Arjuna said: By my hearing the instructions You have kindly given me about these most confidential spiritual subjects, my illusion has now been dispelled.
Commentary by Srila Prabhupada
This chapter reveals Krishna as the cause of all causes. He is even the cause of the Maha-Vishnu, from whom the material universes emanate. Krishna is not an incarnation; He is the source of all incarnations. That has been completely explained in the last chapter.
Now, as far as Arjuna is concerned, he says that his illusion is over. This means that Arjuna no longer thinks of Krishna as a mere human being, as a friend of his, but as the source of everything. Arjuna is very enlightened and is glad that he has such a great friend as Krishna, but now he is thinking that although he may accept Krishna as the source of everything, others may not. So in order to establish Krishna’s divinity for all, he is requesting Krishna in this chapter to show His universal form. Actually when one sees the universal form of Krishna one becomes frightened, like Arjuna, but Krishna is so kind that after showing it He converts Himself again into His original form. Arjuna agrees to what Krishna has several times said: Krishna is speaking to him just for his benefit. So Arjuna acknowledges that all this is happening to him by Krishna’s grace. He is now convinced that Krishna is the cause of all causes and is present in everyone’s heart as the Supersoul.
Commentary by Sri Visvanatha Cakravarti Thakur
In the eleventh chapter, Arjuna, seeing the universal form, praises it in reverence. When Krsna shows himself again, Arjuna becomes pleased.
At the end of the last chapter, hearing about one arhsa of his dear friend, the adipurusa who is the shelter of all the vibhutis, with the words vistabhyaham idam krtsnam ekamsena sthito jagat, Arjuna became submerged in the highest bliss and desired to see that form. He praises what the Lord has just spoken in three verses.
“The words spoken by you giving indications of vibhutis, and concerned with the self (adhyatma) have removed my ignorance concerning your powers (mohah).”