B.G 2.12
न त्वेवाहं जातु नासं न त्वं नेमे जनाधिपाः। न चैव न भविष्यामः सर्वे वयमतः परम् ॥ २-१२॥
na tvēvāhaṁ jātu nāsaṁ na tvaṁ nēmē janādhipāḥ। na caiva na bhaviṣyāmaḥ sarvē vayamataḥ param ॥ 2-12॥
[na tvēvāhaṁ = Never was there, I; jātu nāsaṁ = a time when did not exist; na tvaṁ nēmē = nor you, nor these; janādhipāḥ = princes; na caiva = not surely; na bhaviṣyāmaḥ = shall cease to exist; sarvē vayam = we all; ataḥ param = here after]
Never was there a time when I did not exist, nor you, nor these princes. Surely not, shall we all ever cease to exist hereafter.
Gīta Bhāshya 2.12
The individual being is eternal, similar to God.
किमिति? न त्वेवाहम्। ईश्वरनित्यत्वस्याप्रस्तुतत्वाद्दृष्टान्तत्वेनाह– नत्वेति। यथा अहं नित्यः सर्ववेदान्तेषु प्रसिद्धः एवं त्वमेते जनाधिपाश्च नित्याः ॥ १२ ॥
kimiti? na tvēvāham। īśvaranityatvasyāprastutatvāddr̥ṣṭāntatvēnāha– natvēti। yathā ahaṁ nityaḥ sarvavēdāntēṣu prasiddhaḥ ēvaṁ tvamētē janādhipāśca nityāḥ ॥ 12 ॥
[kim iti? = How so? (why one should not worry?); na tvēvāham = 'na-tvevaham' verse gives answer; īśvaranityatvasya = Eternality of Iswara; aprastutatvāt = there is no need to prove; dr̥ṣṭāntatvēnāha = Hence, taking Him as example; na tvēti = 'na-tve' verse is presented; yathā ahaṁ nityaḥ = The way I am eternal; sarvavēdāntēṣu prasiddhaḥ = I am famous in Vedanta; ēvaṁ tvam = similarly you; ētē janādhipāśca = all these kings; nityāḥ = are eternal.]
How so? (Why should not one worry?) 'na-tvevaham' verse gives the answer. There is no need to prove the eternality of God (Ishwara). Taking Him as an example 'na-tve' verse explains: "The way I am famous in all the Vedas as eternal, similarly you, all the kings, are also eternal".
Gīta Tātparya 2.12
God has no destruction of the body or the self. The individual self is indestructible, but its body goes through destruction.
बन्धुस्नेहाद्धि त्वया स्वधर्मनिवृत्तिः क्रियते। तत्र देहनाशभयात् किं वा चेतननाशभयात्? देहस्य सर्वथा विनाशित्वान्न तत्र भये प्रयोजनम्। न च चेतननाशभयात्। तस्याविनाशित्वादेव। न तावत्परमचेतनस्य मम नाशोस्ति। एवमेव तवान्येषां च।
bandhusnēhāddhi tvayā svadharmanivr̥ttiḥ kriyatē। tatra dēhanāśabhayāt kiṁ vā cētananāśabhayāt? dēhasya sarvathā vināśitvānna tatra bhayē prayōjanam। na ca cētananāśabhayāt। tasyāvināśitvādēva। na tāvatparamacētanasya mama nāśōsti। ēvamēva tavānyēṣāṁ ca।
[bandhusnēhāddhi = due to the friendship with relatives; tvayā = you are; svadharmanivr̥ttiḥ = forsaking own dharma , the sva-dharma; kriyatē = doing; tatra = there; dēhanāśa = destruction of body; bhayāt = fear of; kiṁ vā = or is it; cētana = spirit; nāśa = destruction; bhayāt? = fear of?; dēhasya = The body is; sarvathā = definitely; vināśitvāt = going to get destroyed; na tatra bhayē = no fear here; prayōjanam = is useful; na ca cētana = not also spirit's; nāśa bhayāt = fear of destruction; tasya = it is; avināśitvādēva = without destruction; na = no; tāvat = As I am; paramacētanasya = supreme being; mama = for me; nāśōsti = destruction; ēvamēva = Similarly; tava anyēṣāṁ ca = for you all as well;]
Because of friendship of relatives, you are forsaking your own duty (sva-dharma). Is this because of the fear of destruction of their body, or their self? There is no use fearing for the body, as it is definitely going to get destroyed. No need to fear for their being, as it is indestructible. As I am supreme being, I have no destruction. It is the same for you and everyone else as well:
"नित्यो नित्यानां चेतनश्चेतनानाम् एको बहूनां यो विदधाति कामान्" ॥ इत्यादिश्रुतेः।
"nityō nityānāṁ cētanaścētanānām ēkō bahūnāṁ yō vidadhāti kāmān" ॥ ityādiśrutēḥ।
['nityō nityānāṁ = he is the eternal among everlasting entities; cētanaścētanānām = he is the sentient among the sentients; ēkō bahūnāṁ = He is one among many; yō vidadhāti = He grants everyone's; kāmān'' = desires; ityādiśrutēḥ = So states Vedas; ]
"He is eternal among the everlasting entities. He is the sentient among the sentients. He is one among many. He grants everyone’s desires"–So states Vedas
"स्वदेहयोगविगमौ नाम जन्ममृती पुरा । इष्येते ह्येव जीवस्य मुक्तेर्न तु हरेः क्वचित्" ॥ इति स्कान्दे।
"svadēhayōgavigamau nāma janmamr̥tī purā । iṣyētē hyēva jīvasya muktērna tu harēḥ kvacit" ॥ iti skāndē।
[svadēha = its own body; yōgavigamau = union and disunion; nāma janmamr̥tī = called birth and death; purā = body; iṣyētē hyēva jīvasya = The being obtains causal and experiences; muktērna tu harēḥ = till liberation, but not for Hari; kvacit'' = ever; iti skāndē = States Skanda Purana.]
"The being obtains a causal body and experiences birth and death in the form of union and disunion with its body till its liberation. But never for Hari (God)."–states Skanda Purana
ईश्वरस्यापि युद्धगतत्वान्मोहात् तस्याप्युभयविधानित्यत्वशङ्काप्राप्तौ तदपि निवार्यते न त्वेवाहमिति।
īśvarasyāpi yuddhagatatvānmōhāt tasyāpyubhayavidhānityatvaśaṅkāprāptau tadapi nivāryatē na tvēvāhamiti।
[īśvarasyāpi = Even though he is Lord; yuddhagatatvān = fighting in the war; mōhāt = due to delusion; tasyāpī = Even for Him (Krishna); ubhaya vidhā = both the type; nityatva = eternality; śaṅkāprāptau = in case of doubt; tadapi = that is also; nivāryatē = clarified; na tvēvāhamiti = by 'natvevaham'.]
Even though Krishna is Lord, because of delusion, if someone doubts eternality in Him of either body or self, it is clarified by stating 'natvevaham' i.e., "never was there a time when I did not exist".
यद्यप्येषा शङ्कार्जुनस्य नास्ति। तथापि प्राप्तलोकोपकारार्थं भगवता निवार्यते। एकान्ते कथयन्नपि व्यासरूपेण तदेव लोके प्रकाशयिष्यति हि ॥१२ ॥
yadyapyēṣā śaṅkārjunasya nāsti। tathāpi prāptalōkōpakārārthaṁ bhagavatā nivāryatē। ēkāntē kathayannapi vyāsarūpēṇa tadēva lōkē prakāśayiṣyati hi ॥12 ॥
[yadyapyēṣā śaṅkārjunasya nāsti = These doubts are not with Arjuna; tathāpi prāptalōkōpakārārthaṁ bhagavatā nivāryatē = Even then, for the sake of benefiting the world the Lord clarifies; ēkāntē kathayannapi = Even though this happened only between Arjuna and Krishna; vyāsarūpēṇa = In the form of Vyasa; tadēva lōkē prakāśayiṣyati hi = it is published to the world.]
These doubts are not with Arjuna. Even then the lord clarifies for the sake of benefiting the world. Even though this episode happened only between Arjuna and Krishna, Vyasa published it in the world.