The eleventh chapter of the Bhagavad Gita is Vishwaroopa Darshana Yoga. In this chapter, Arjuna requests Krishna to reveal His Universal Cosmic Form that encompasses all the universes, the entire existence. Arjuna is granted divine vision to be able to see the entirety of creation in the body of the Supreme Lord Krishna.
Sanjaya said: Thus, having spoken to Arjuna in that manner, Vasudeva showed His own form again. And He, the exalted One, reassured this terrified one by again becoming serene in form.OPEN VERSE
Arjuna said: O Janardana, having seen this serene human form of Yours, I have now become calm in mind and restored to my own nature.OPEN VERSE
The Blessed Lord said: This form of Mine which you have seen is very difficult to see; even the gods are ever desirous of a vision of this form.OPEN VERSE
Not through the Vedas, not by austerity, not by gifts, nor even by sacrifice can I be seen in this form as you have seen Me.OPEN VERSE
But, O Arjuna, by single-minded devotion am I-in this form-able to be known and seen in reality, and also be entered into, O destroyer of foes.OPEN VERSE