O best of the Bhāratas, see here the different manifestations of Ādityas, Vasus, Rudras, Aśvinī-kumāras and all the other demigods. Behold the many wonderful things which no one has ever seen or heard of before.
PURPORT SIGNIFICADO
Even though Arjuna was a personal friend of Kṛṣṇa and the most advanced of learned men, it was still not possible for him to know everything about Kṛṣṇa. Here it is stated that humans have neither heard nor known of all these forms and manifestations. Now Kṛṣṇa reveals these wonderful forms.