Just like you have got living entities in the sea. There are hundreds and thousands. Jalajā nava-lakṣāṇi (Padma Purāṇa). There are nine lakhs species of aquatic animals. But they are living in the water. They have got particular type of body. You cannot say, because you cannot live within the water, you cannot say, "No, no, there cannot be any living entity." This is nonsense. The living entities, another name is sarva-ga: he can live everywhere. It is not a fact that living entities live only in certain particular place. No. Sarva-ga, anywhere in God's creation there are living entities. This is śāstric vision.
So in the sun planet also there are living entities, cities, just like here. Otherwise, how Kṛṣṇa can say, imaṁ vivasvate yogaṁ proktavān aham avyayam (BG 4.1)? Kṛṣṇa is telling lie, that "I spoke this science of Bhagavad-gītā to the sun-god"? Now, according to our calculation nobody can go to the sun planet, and where is the scope of speaking there, and to whom speaking? But Kṛṣṇa says, "Yes." Imaṁ vivasvate yogaṁ proktavān aham, "I said," avyayam, "imperishable knowledge." Vivasvān manave prāha. So from this version we can understand, in the sun planet there are living entities, and the chief man, or chief demigod, is the sun-god, whose name is Vivasvān. So his body must be fiery; otherwise how he can live there? And the inhabitants there also. So we are thinking from here that nobody can live there, but that's not the fact. We are calculating via our own experience. Therefore we cannot have perfect knowledge by speculating our experience. It is not possible. We must go to a person whose experience is beyond our experience. That is called guru.
Tad-vijñānārthaṁ sa gurum evābhigacchet (MU 1.2.12). Guru means heavy. If guru is as good as I am, then what is the use of taking knowledge from him? Guru must be heavier. So who can become more heavier than Kṛṣṇa? Mattaḥ parataraṁ nānyat kiñcid asti dhanañjaya (BG 7.7). There is nobody heavier. And Kṛṣṇa proved it when He was a child. When He was a boy of seven years old He proved how heavy, that He lifted the Govardhana Hill, and it rested on Kṛṣṇa's finger continually for seven days. Just imagine how heavy He is. So in this way we have to understand Kṛṣṇa. And if we understand Kṛṣṇa from that spirit, from that angle of vision, then we become perfect. As it is said here, jñeyaṁ yat tat pravakṣyāmi yaj jñātvā 'mṛtam aśnute. You become immortal.
This is confirmed in the Fourth Chapter: janma karma me divyaṁ yo jānāti tattvataḥ (BG 4.9). If you simply understand Kṛṣṇa in truth, not superficially, but in fact, then what is the result? The result is, tyaktvā dehaṁ punar janma naiti. Punar janma. Punar janma, next, again if I take a material body, then again I'll have to die. Anyone who has got this material body, he has to die. Janma-mṛtyu. One who is born, he must die. But here Kṛṣṇa says, punar janma naiti: "No more birth." Then there is no more death. Because if there is birth, there is death, and if there is no birth, there is no death. That is immortality, amṛta. That is amṛtatva. So amṛtatvāya kalpate.