B.G 2.20

न जायते म्रियते वा कदाचिन् नायं भूत्वा भविता वा न भूयः । अजो नित्यः शाश्वतोऽयं पुराणो न हन्यते हन्यमाने शरीरे ॥ २-२०॥

na jāyatē mriyatē vā kadācin nāyaṁ bhūtvā bhavitā vā na bhūyaḥ । ajō nityaḥ śāśvatō’yaṁ purāṇō na hanyatē hanyamānē śarīrē ॥ 2-20॥

The Lord is neither born nor does he die. The ever existent neither come into being nor ceases to exist. The Jīva transmigrating from one body to another is unborn, eternal, and permanent (as he is similar to Lord). The Jīva is not destroyed when his body is destroyed.

Gīta Tātparya 2.20

There are two references to 'unborn' and 'permanent' in the above verse. So, one refers to the Lord, and the other to the Jīva. Else there will be a redundancy error. The word 'Purāna' refers to transmigrating Jīva. Scriptures state Jīva to be permanent, and thus the dependent nature of Jīva is also permanent.

There is scriptural evidence as well to prove the eternality of the Lord and Jīva. So it is stated 'najāyate mriyate'. 'nāyam bhūtva' - means the Parama-purusha, the supreme being, exists at all times. 'bhavita nā' - denies any relation (of the Lord) to the physical body. Death is well known as separation from the body. Insentient objects like pot do not have a transactional relationship related to death. Destruction of such insentient forms is certainly not spoken in terms of death.

The words 'ajah' i.e. unborn and 'nitya'i.e. everlasting, refer to Jīva, the being. Else it is repetition and results in redundancy error. The Jīva is said to be 'shāshvata', i.e. permanent. So, the dependent attribute of Jīva is natural and a permanent character that does not change with time.

“Limited power, limited knowledge, dependence, incompleteness, and being a subsistence being are Jīva’s natural qualities. To be a living being, i.e. to be Jīva, is the opposite of being the 'Īswara', which means the Lord. Hence, the wise declare the Jīva to be eternal.” - stated thus in Mahā Vishnu Purāna.

As Jīva obtains various bodies, he is called 'Purāna'