O Bhagavan, overjoyed am I to have seen (Your Form) which has never been seen before, yet my heart is agitated with terror; therefore show me that form of Yours. O God of gods! O Abode of the universe, have mercy! (Bhagavad Gita Chapter XI – Verse 45)
The strain becomes too much for Arjuna’s mind. Even joy becomes painful in its most extreme form and when sustained too long. Hitherto-unknown emotions have agitated Arjuna’s mind. An excess of feeling, astonishment, fear, love, awe and bewilderment have exhausted his mental power. Enough! The vision I can never forget. Your true nature I know now once and for all. Now let me see You again as before, as my friend. How?
I desire to see You as before, with diadem, mace and discus; O Universal Form of a thousand arms, assume that same four-armed form. Bhagavad Gita Chapter XI – Verse 46)
We remember that Sri Krishna was the incarnation of Vishnu, the Preserver, endowed with four arms, who came for the preservation of dharma. That is the peaceful attribute of Ishvara, the Narayana who dwells in the hearts of all beings. But on the battlefield, where peace is re stored through destruction, Sri Krishna assumes the terrible form of the Destroyer. That is what Arjuna saw. Now he wants to see the old familiar form again, the incarnation of the Preserver, Krishna, the son of Vasudeva. Arjuna did not know before that Sri Krishna was a full incarnation and that therefore He could assume all forms.
Full incarnation means that He had full power. He was not limited in any sense. Other incarnations may come for a certain race or country or to remove a certain phase of ignorance, of adharma (evil). But Sri Krishna came for the whole world, for all humanity, to establish Truth once for all. Other incarnations are like one of the Upanishads. Sri Krishna was the whole of the Vedas.
And now comes a word of great encouragement for Arjuna. He was frightened. So Bhagavan consoles Him. Fear not. Seeing Me thus, you have been highly favoured. None has ever seen Me as you saw Me. It is through My great love for you that I showed you that form.
Why did the Lord show this form to Arjuna? Through His grace, through His love, yes, but that grace and love He extends to everyone. Only others do not avail themselves of it. But whoever unfurls the sail the wind of grace will carry along.