dyaavaaprathivyoridamantaram hi vyaaptam tvayaikena dishashcha sarvaahaa |
drashtvaadbhutam roopamagram tavedam lokatrayam pravyathitam mahaatman || 20 ||

This distance between heaven, earth is and all directions is pervaded only by you alone. Having seen this, your fascinating and terrible form, the three worlds are afraid, O great one.
dyaavaaprathivyoho : heaven and earth
idam : this
antaram : distance
hi : only
vyaaptam : pervaded
tvayaa : by you
ekena : one
dishashcha : directions
sarvaahaa : all
drashtvaa : having seen
adbhutam : fascinating
roopam : form
agram : terrible
tava : your
idam : this
lokatrayam : three worlds
pravyathitam : afraid
mahaatman : O great one
Nowadays, computers can be trained to recognize objects and faces. They do this by first taking a snapshot of a scene, and then differentiating between what is space is what is not. If they can do this differentiation correctly, they can compare the outlines of the “not-space” with outlines of familiar objects to arrive at a conclusion such as “this is a box” and so on.
Our eyes work in pretty much the same way. Whenever they see space, they do three things. First, they separate whatever they see as not-space and call those things “objects”. Next, they send those objects to the mind which uses its memory to say “this is a box and a key”. But in addition to recognizing objects, the mind also automatically adds another thought. Since the box and key are separated by space, they are far away from me and therefore not a part of me.
Our minds are conditioned to believe that Ishvara is sitting somewhere far away. He is separated from us by space, by distance. But when Arjuna saw the cosmic form, he realized that space is not different from Ishvara. In fact, Shri Krishna himself said that space is part of his nature in the seventh chapter. Ishvara is not separate and far away from us, he is with us all the time. In fact, he only exists, “ekena”, all alone, by himself. We are not different from him. This is the main point of this shloka. Only by constantly remembering the cosmic form will we truly understand this message.
Now, Ishvara’s ugra roopa, his terrible form, slowly replaces his saumya roopa, his pleasant for. For every pleasant experience in the world, there has to be a corresponding unpleasant experience as well. Once you label something as “good”, there will be something “bad” by default. Seeing this frightful form of Ishvara, with fire coming out of all his mouths, all the three worlds were beginning to worry.