न त्वेवाहं जातु नासं न त्वं नेमे जनाधिपाः | न चैव न भविष्यामः सर्वे वयमतः परम् ||२-१२||
na tvevāhaṃ jātu nāsaṃ na tvaṃ neme janādhipāḥ .
na caiva na bhaviṣyāmaḥ sarve vayamataḥ param ||2-12||
Nor at any time indeed was I not, nor thou, nor these rulers of men, nor verily shall we ever cease to be hereafter.
In simple words
Krishna tells Arjuna: "There was never a time when you did not exist. There was never a time when I did not exist. And there will never be a time when any of us will stop existing."
Contemporary scholarly and practical interpretations for modern seekers.
Swami Sivananda
2.12 न not? तु indeed? एव also? अहम् I? जातु at any time? न not? आसम् was? न not? त्वम् thou? न not? इमे these? जनाधिपाः rulers of men? न not? च and? एव also? न not? भविष्यामः shall be? सर्वे all? वयम् we? अतः from this time? परम् after.Commentary -- Lord Krishna speaks here of the immortality of the Soul or the imperishable nature of the Self (Atman). The Soul exists in the three periods of time (past? present and future). Man continues to exist even after the death of the physical body. There is life beyond.
Swami Chinmayananda
This interpretation draws on a specific tradition and may not represent the view of any single school. For authoritative guidance within a specific tradition, seek a qualified teacher.
Here, the Lord makes a clear declaration that the atman, the eternal self that dwells within the body, has embarked upon a great pilgrimage. During the course of this journey, it assumes various bodies for a time and identifies itself with them, thereby gaining particular experiences. The presence of Shri Krishna, Arjun, and the other kings in those specific bodies was no mere accident. They did not emerge from nothingness, nor shall they become void after death. Through authentic philosophical inquiry, a human being can understand the continuous chain of events spanning past, present, and future. The atman, remaining itself, appears to experience the circumstances it encounters by assuming many bodies. This is the celebrated doctrine of rebirth in Hindu philosophy.
The greatest opponents of this principle appear not to have studied their own scriptures thoroughly. Even Jesus Christ, whether directly or indirectly, accepted this principle. When he told his disciples that John was Elijah, he affirmed it. Origen, a learned Christian scholar, explicitly stated that every human being receives this body as the fruit of the virtues accumulated in previous lives. There is no great thinker who has not, directly or indirectly, accepted the principle of previous birth. Gautama Buddha constantly referred to his former lives. Both Virgil and Ovid accepted this principle as self-evident truth. Josephus stated that in his time, the Jews held considerable faith in the doctrine of rebirth. Solomon, in the Book of Wisdom, declared that being born in a healthy body with healthy limbs is the fruit of virtuous deeds performed in a previous life. And who does not know the words of the Prophet Muhammad of Islam, in which he said: "I died as a stone and became a plant; I died as a plant and became an animal; I died as an animal and became a human being. Why then should I fear death? When have I ever been diminished by dying? When I die as a human, I shall become an angel." In the centuries that followed, the German philosophers Goethe, Fichte, Schelling, and Lessing also accepted this principle. In the twentieth century itself, philosophers such as Hume, Spencer, and Max Müller have regarded it as an undisputed principle. Even the celebrated poets of the West, wandering in the clear expanse of imagination and inspired by the divine muse, have experienced this very principle, among whom Browning, Rossetti, Tennyson, and Wordsworth are prominent names.
The doctrine of rebirth is not merely the idle fancy of metaphysical thinkers. The day is not far when, due to the rapid advancement in the field of psychology, the facts being gathered will, through their weight and influence, compel Western nations to rewrite their scriptures. Those who wish to understand the reality of life without prejudice or coercion are troubled by the inequalities visible in the world. These cannot all be dismissed as mere coincidence. If we accept reason, we must acknowledge the existence of the jiva, the individual soul, as distinct from the body. Mozart provides a striking example. He composed instrumental works at the age of four, presented performances before people in his fifth year, and created musical dramas at the age of seven. If we examine the lives of Shankaracharya and others of India, we find that they possessed extraordinary knowledge even in childhood. Without accepting the doctrine of rebirth, these remarkable events must be dismissed as mere chance and cast into the dustbin.
Many events that prove rebirth are observed, yet they are seldom collected as evidence. As I have said, the modern world still has research to undertake regarding this great self-evident law of life. A person of immature understanding may initially doubt this principle. When the Lord said that none of them would perish, Arjun, being an ordinary person of the world, could not fully grasp his words. He looked toward Shri Krishna with a questioning expression and sought further clarification.
"Why should we not grieve for them? Because in their essential nature, all of these are eternal." How...? The Lord says: