Verse 13

In plain words

But in what way is the ātman eternal? With that question in view, He gives an example —

Having a body is what makes someone 'embodied.' And in this one present body that the Self carries, there are three distinct stages: childhood, youth, and old age, each utterly unlike the others. When the first stage ends, nothing in the Self ends. When the second stage begins, nothing in the Self begins. So what's actually happening? What we observe is simply this: the very same unchanging Self moves through the second stage and the third. And it's exactly the same when the body itself changes — a different body is just 'another body,' and taking it on is 'taking on another body' — still happening to that same unchanging Self. That's the whole meaning. 'The steadfast one' means the wise person: knowing this, he isn't shaken, and he doesn't fall into confusion.

Close to the Sanskrit

On that point, 'how indeed is the Self eternal?' — thus, He states an illustration —

'Body' [is that which] this one has — thus [he is called] 'embodied.' Of that embodied one, possessing a body, of the Self, in this present body — in whatever manner — [there is] childhood, the state of being a child, the condition of infancy; youth, the state of being young, the condition of middle age; old age, the loss of vigor, the condition of decrepitude — these three states are distinct from one another. Of these, in the destruction of the first state, there is no destruction [of the Self]; in the arising of the second state, there is no arising of the Self. What then [is the truth]? The attainment of the second and third states is observed [to belong] precisely to the unchanging Self. Likewise, in the same way, another body, different from this body, is 'another body'; the attainment of that is 'the attainment of another body,' [belonging] precisely to the unchanging Self — such is the meaning. 'The steadfast one' means the wise one; there, this being so, he is not confounded, nor does he fall into delusion.

In plain words

Arjuna's sight rested on bodies alone, and the way to bestow on him the sight of the “Ātma” is to separate body from Ātma: that separation is the goal of all sādhanas. Kṛṣṇa's teaching exists to teach this; this is its whole subject. Though Arjuna did not voice his doubts, Kṛṣṇa himself stated those doubts and gave the answer. “Arjuna! You grieve that you, and the royal kinsmen bound to you, will die because of you. You have recited dharmas, but the wise grieve neither for the dead nor for the living. Do you ask why they do not grieve? What you grieve for is bodies, is it not! Did you grieve over the states, the changes, the body passed through before? From infancy to childhood, from childhood to boyhood, from boyhood to youth, from youth to old age, and then the state of death. Death too is one of those states, is it not? How much did you grieve over those four states, that you should grieve over this state of death? Where is the body that played with your brothers when you were a child? It is not there, is it! The boy's body that bound Dhṛṣṭadyumna and brought him that day, is it here today? Yet you remember that event even now, do you not? In the same way, though your bodily states change, the Prajñāna that is the “Ātma” keeps for ever its immortal svarūpa. This is the mark of the jñānis.”

In plain words

Though it dwells together with bodies, the “Ātma” remains beyond the properties of the guṇas. Childhood, boyhood, youth, old age and the rest (the states) come within the body; the attaining that comes after the body is just the same. Making the chariot shake, Kṛṣṇa told him emphatically that the dhīra does not grieve over this.

To this Arjuna asks, his mind full of doubt: “Svāmī! You said, did you not, that the changes of body are just like the changes of state? But what happens in one state stays in memory after we pass to another, does it not? Then does what happened in another body not stay in memory? How does what you said fit this?”. “Only the one point of likeness is to be taken; taking it in every respect will not do. Though the states change, the Ātma does not change! In the same way, though the bodies change, the Ātma does not change! In the illustration, take only this much.”

But Arjuna went on to another point. This doubt is not Arjuna's alone; knowing that such doubts come to ordinary people, God said, “The dhīra is not deluded by this,” and answered that doubt right there, without delay. “Arjuna! Through the changes of state the Buddhi can keep its memory up to a point; but at the time of death, that is, in the conditions of passing into another body, the Buddhi is shattered. With that blow it forgets everything that has gone by, all at once. Remembering and forgetting are a property of the Buddhi, not a property of the Ātma.”

“Now take another example. Suppose you are twenty-five years old. If someone asked you where you were on some day ten years ago, you could not say. But it is true that you were, is it not? You certainly cannot say, 'I was not,' can you? So it is with what happens across bodies too! You were there, only the events are not in your memory. In just this matter, the one who has strength of Buddhi does not fall into delusion. Only such a person do they call a “jñāni”. The Ātma is not something that goes; the body is not something that stays. Well then, if you grieve over their death, does that give their Ātma any joy? To say so is more foolish still. Whatever is done to it, the Ātma knows no sorrow.”