Perfect knowledge of the soul's transmigration comes only through hearing from authorized Vedic sources, not imperfect senses.Listen — Srila Prabhupada Uvaca
Bhagavad-gītā 2.13 — October 12, 1972, Manila 721012BG-MANILA [45:24 Minutes] Bg-02.13_721012BG-MANILA Prabhupāda: dehino 'smin yathā dehe kaumāraṁ yauvanaṁ jarā tathā dehāntara-prāptir dhīras tatra na muhyati [Bg. 2.13] So this dead body, when a man dies, dhīras tatra na muhyati. Those who are dhīra—dhīra means sober—they are not bewildered. There are two classes of men: dhīra and adhīra. Dhīra means those who are not agitated; they know things as they are.
So adhīra means those who are uncontrolled. The poet Kalidāsa has described dhīra and adhīra with reference to Lord Śiva in his book Kumāra-sambhava. So dhīra means a person who is not agitated in spite of the cause of agitation being present. There are so many causes of agitation, but a person, in spite of being persuaded by the cause of agitation...
Just like a young man and young woman, when they are present, naturally they become agitated. In the śāstras it is said just like fire and butter. If you put butter before the fire, automatically it melts. Similarly, a woman is considered as fire and the man is considered as butter.
So this is natural. But a person who is not agitated, he is called dhīra. So when a man dies, the man's relatives lament, "Oh, my father has gone," "My sister has gone," "My wife..." But if you become dhīra, then you are not bewildered. Just like your friend or your father moves from this apartment to another apartment, who is agitated?
No, that's all right. He was in this apartment, now he has gone to another apartment, so there is no question of agitation or being perturbed. Similarly, one who knows the causes of transmigration of the soul from one body to another, he is not agitated at the death of his friend or relative. He knows everything, and he knows where his friend has gone with reference to the śāstra. Just like your friend has gone to India.
How do you know? You know that he purchased a ticket for India and he has gone to India, so there is no need of agitation, "Oh, where he has gone? Where he has gone? Where he has gone?" Similarly, when a man dies, one who is dhīra...
Here especially the word is used, dhīras tatra na muhyati. Muhyati means bewildered. Tathā dehāntara-prāptiḥ [Bg. 2.13]. Just like the parents.