तथा शरीराणि विहाय जीर्णा-
न्यन्यानि संयाति नवानि देही ।।
गीता, २, २२
As a person puts on new garments, giving up old ones, the soul similarly accepts new material bodies, giving up old and useless ones.
In Sankhya Yoga, Supreme Personality of Godhead explained son of Kunti (Arjuna), about soul and material body.
Arjuna was bewildered by thinking to counterattack on Bhisma and Drona who were worthy of his worship.
Godhead said: Never there was time, I did not exists, nor you, nor all of these Kings; nor in the future shall any of us cease to be.
As the embodied soul continuously passes, in his body, from boyhood to youth to old age, the soul similarly passes into another body at death. A sober person is not bewildered by such a change.
One should note down, for the soul there is neither birth nor death at any time. He has not come into being, does not come into being and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when body is slain.
The soul can never be cut into pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind.
The individual soul is unbreakable and insoluble and can neither be burned and dried. He is everlasting, present everywhere, unchangeable, immovable and eternally same.
One who has taken birth is sure to die, and after death one is sure to take birth. Therefore, in the unavoidable discharge of our duties, one should not lament.
जातस्य हि ध्रुवो मृत्यू