Kṛṣṇa is describing, "My abode, how it is. In that sky, where My abode is there, there is no necessity of sunlight, there is no necessity of moonlight, there is no necessity of electricity." Now you cannot find such abode within this universe. You travel with your sputnik or any machine, you find out some place where there is no sunlight, there is no moonlight. The sunlight is so extensive, all over the universe. Where you'll find that place? That means that place is beyond the sky. That is also stated, paras tasmāt tu bhāvo 'nyo 'vyakto 'vyaktāt sanātanaḥ (BG 8.20).
Beyond this material nature there is another, spiritual nature.
So we do not know what is the formation of this material nature, and what to know about the spiritual nature. Then you have to hear from Kṛṣṇa, who lives there. Otherwise, you remain nonsense all your life. Here is the information. How can you know which you cannot reach, cannot know with your senses are so imperfect? How can you know? Simply you have to hear.
Just like you have to hear about your father from the mother. There is no other way. The father certifies, mother certifies, "Here is your father," you have to accept. You cannot make any experiment. Beyond your means. Similarly, if you want to learn about the spiritual sky in God's kingdom, then you have to simply hear from the authority. There is no question of experimental knowledge. Simply hearing.
So hearing means—just like you have to believe some gentleman as your father, hearing from the authority of your mother—simply from the Vedic literature, which is accepted as the mother, authority of mother, knowledge. Mother authority. Veda-mātā. It is called Veda-mātā. Veda means knowledge, and it is received from the mother.