In the Brahma-samhita it is stated that the Lord is eternally situated in hundreds and thousands of forms, and the main forms are those like Rama, Nrsimha, Narayana, etc. There are innumerable forms. But Arjuna knew that Krsna is the original Personality of Godhead assuming His temporary universal form. He is now asking to see the form of Narayana, a spiritual form. This verse establishes without any doubt the statement of the Srimad-Bhagavatam that Krsna is the original Personality of Godhead and all other features originate from Him. He is not different from His plenary expansions, and He is God in any of His innumerable forms. In all of these forms He is fresh like a young man. That is the constant feature of the Supreme Personality of Godhead. One who knows Krsna at once becomes free from all contamination of the material world.