Devotee (2): Swāmījī, I think this man's question needs a little bit more clarification. He was asking how do we know what Kṛṣṇa dictates, by what authority. How do we know how we can serve Kṛṣṇa? Is that your question? How do we know how we can serve Kṛṣṇa?
Guest (1): Yes. Well, I, one thing . . .
Prabhupāda: That I have answered, that you can serve Kṛṣṇa by following the dictation of Kṛṣṇa. Is it not clear? Then the next question may be how you receive dictation of Kṛṣṇa. Is that?
Guest (1): Right. Yes. That would be the next question (laughter)
Prabhupāda: Yes. That is answered in the Bhagavad-gītā, Fourth Chapter (laughter) evaṁ paramparā-prāptam imaṁ rājarṣayo viduḥ (BG 4.2). Just like you call this "table." How you understand this is table? You have taken the idea from your parents. And wherefrom your parents got this idea that this is a table? They also got from their parents. Therefore this idea of table—you do not say anything else—is received by succession. Similarly, you can receive succession order from Kṛṣṇa through spiritual master.
Guest (2): Swāmījī, what . . . you said that sleep is complete waste of time.
Prabhupāda: Yes. Because you cannot work then.
Guest (2): What about dreaming?
Prabhupāda: Dreaming is still waste of time. (laughter)
Guest (2): Is it possible to have Kṛṣṇa consciousness when you are asleep?
Prabhupāda: Dreaming is practically interaction of the activities, mental interaction of the activities in which you are engaged. You dream in different way, I dream in different way. So when the body is tired, it cannot work. It stops functioning. The mind works. So dreaming is the function of the mind. That's all. So . . . huh?
Guest (2): . . . (indistinct)
Prabhupāda: No. It is not from the spiritual platform, it is from the mental platform. In the spiritual platform, that is called suṣupti. There is no gross or material function of this contamination. So those who are advanced, they also dream Kṛṣṇa consciousness. Of course, that requires time to make little advancement. But after all, dream is the activities of the mind. Just like we work, that is the activities of the gross senses. Similarly, we work also on mental platform. That is called dream.
Guest (3): Are we to take Kṛṣṇa conscious dreams seriously or as some illusion?
Prabhupāda: Well, that depends on your particular position, you see. Sometimes a Kṛṣṇa conscious persons dreams very seriously. Sometimes communication is there by dream.
Yes?
Guest (4): Normal sleep for a man would be about eight hours. So is it possible to train the body through the use of yoga to decrease the sleep period down to about three hours or two hours?
Prabhupāda: Oh, yes. Yes. Rūpa Gosvāmī, he used to sleep only for one and a half hours.