Bg. 2.13

देहिनोऽस्मिन्यथा देहे कौमारं यौवनं जरा ।
तथा देहान्तरप्राप्तिर्धीरस्तत्र न मुह्यति ॥१३॥

Text

dehino ‘smin yathā dehe
kaumāraṁ yauvanaṁ jarā
tathā dehāntara-prāptir
dhīras tatra na muhyati

Synonyms

dehinaḥplugin-autotooltip__small plugin-autotooltip_bigdehinaḥ

for the embodied; of an embodied soul; of the embodied; of the embodied souls; of the father possessing a material body; of the living entity; of the person in danger of death; the living entities who have accepted material bodies; to other living entities.
—of the embodied; asminplugin-autotooltip__small plugin-autotooltip_bigasmin

during this period (one day of Brahmā); for Him (the Supreme Lord); for Lord Kṛṣṇa; herein; in the chain of; in the matter; in them; in this; in this body; in this cow shed; in this form of; in this world; on this; on this path of sense enjoyment; on this planet earth; this; this very life; to this body; unto Kṛṣṇa; up till now; when this; within this.
—in this; yathāplugin-autotooltip__small plugin-autotooltip_bigyathā

according to; accordingly as; and as; anywhere; as (He likes); as; as advised by his father; as also; as far //as// possible; as far as; as follows; as has; as He desires; as if; as if it were; as is; as it; as it is; as it is now; as it should have been; as it was; as it was done; as it were; as many; as much; as much as (deserved); as much as; as requested; as they are; as they told it; as they were; as well as; as you; by which; development of austerity and penance; duly; even as; exactly as; exactly like; fittingly; for the forefathers and the Supreme Personality of Godhead; how; in any manner; in order that; in the matter of; in what way; in which manner; in which way; in whichever manner; inasmuch as; just as; just as if; just like; like; like Him; or just as; properly; since; so; so that; so you inform me; the manner in which; where; wherever; without deviation.
—as; deheplugin-autotooltip__small plugin-autotooltip_bigdehe

body; his body; in the bodies; in the body; in the material body; in the matter of the material tabernacle; in this body; of the body; on the body; the body; towards the body; when the body.
—in the body; kaumāramplugin-autotooltip__small plugin-autotooltip_bigkaumāram

boyhood; named the Kumāras (unmarried); the age of childhood.
—boyhood; yauvanamplugin-autotooltip__small plugin-autotooltip_bigyauvanam

youth.
—youth; jarāplugin-autotooltip__small plugin-autotooltip_bigjara

old age; old age, invalidity.
—old age; tathāplugin-autotooltip__small plugin-autotooltip_bigtatha

so.
—similarly; dehāntaraplugin-autotooltip__small plugin-autotooltip_bigdehāntara

transference of the body.
—transference of the body; prāptiḥplugin-autotooltip__small plugin-autotooltip_bigprāptiḥ

achievement; allowing approach; the attainment.
—achievement; dhīraḥplugin-autotooltip__small plugin-autotooltip_bigdhirah

(he can become) a most perfect, sober person; one who is sober because of advanced devotional service; self-controlled; sober; sober, not disturbed; steadfast; steadily; steady; the fully satisfied; the most learned person, Mahārāja Ambarīṣa; the pacified; the sober; undisturbed.
—the sober; tatraplugin-autotooltip__small plugin-autotooltip_bigtatra

about the well of nectar; all those; among the sons; among them; and there; as well as; at that time; at that very spot; because of; here; in Him; in such; in such a condition; in such a position; in such a subject matter; in such activities; in that; in that case; in that connection (getting out of the entanglement of material conditioning); in that connection; in that direction; in that dynasty; in that forest; in that function; in that heavenly planet; in that meeting; in that ninth period of Manu; in that period (the eleventh //manvantara//); in that period; in that period of Manu; in that place; in that sacrifice; in that sixth //manvantara//; in that way; in the assembly; in the battlefield; in the eighth //manvantara//; in the forest; in this //manvantara//; in this; in those //manvantara// periods; in those hellish planets; in victory or defeat; in whom; inside the house of Narakāsura; on that hill; on the bank of the river; on the spot; on this fact; standing there; than them; that; then; then and there; thereafter; therefore; therein; thereof; thereon; thereupon; to that household life; upon doing this; within the wide-open mouth of Kṛṣṇa.
—thereupon; naplugin-autotooltip__small plugin-autotooltip_bigna

//never//; //not//; are not; but not; cannot; certainly not; could not; did not; do not; does it not; does not; is not; it is not; it is not so; may not; neither; never; never does; never to be; no; no one; none; nor; not; not like that; not preceded by //oṁ//; not suitable; nothing; or not; shall not; should never; there is none; there is not; there should not be; was not; whether; without.
—never; muhyatiplugin-autotooltip__small plugin-autotooltip_bigmuhyati

become bewildered; becomes bewildered; becomes illusioned; bewildered; deluded; is bewildered.
—deluded. 

Translation

As the embodied soul continually passes, in this body, from boyhood to youth to old age, the soul similarly passes into another body at death. The self-realized soul is not bewildered by such a change. 

Purport

Since every living entity is an individual soul, each is changing his body every moment, manifesting sometimes as a child, sometimes as a youth, and sometimes as an old man. Yet the same spirit soul is there and does not undergo any change. This individual soul finally changes the body at death and transmigrates to another body; and since it is sure to have another body in the next birth—either material or spiritual—there was no cause for lamentation by Arjuna on account of death, neither for Bhīṣma nor for Droṇa, for whom he was so much concerned. Rather, he should rejoice for their changing bodies from old to new ones, thereby rejuvenating their energy. Such changes of body account for varieties of enjoyment or suffering, according to one’s work in life. So Bhīṣma and Droṇa, being noble souls, were surely going to have either spiritual bodies in the next life, or at least life in heavenly bodies for superior enjoyment of material existence. So, in either case, there was no cause of lamentation. 

Any man who has perfect knowledge of the constitution of the individual soul, the Supersoul, and nature—both material and spiritual—is called a dhīra or a most sober man. Such a man is never deluded by the change of bodies. The Māyāvādī theory of oneness of the spirit soul cannot be entertained on the ground that spirit soul cannot be cut into pieces as a fragmental portion. Such cutting into different individual souls would make the Supreme cleavable or changeable, against the principle of the Supreme Soul being unchangeable. 

As confirmed in the Gītā, the fragmental portions of the Supreme exist eternally (sanātana) and are called kṣara; that is, they have a tendency to fall down into material nature. These fragmental portions are eternally so, and even after liberation, the individual soul remains the same—fragmental. But once liberated, he lives an eternal life in bliss and knowledge with the Personality of Godhead. The theory of reflection can be applied to the Supersoul who is present in each and every individual body and is known as the Paramātmā, who is different from the individual living entity. When the sky is reflected in water, the reflections represent both the sun and the moon and the stars also. The stars can be compared to the living entities and the sun or the moon to the Supreme Lord. The individual fragmental spirit soul is represented by Arjuna, and the Supreme Soul is the Personality of Godhead Śrī Kṛṣṇa. They are not on the same level, as it will be apparent in the beginning of the Fourth Chapter. If Arjuna is on the same level with Kṛṣṇa, and Kṛṣṇa is not superior to Arjuna, then their relationship of instructor and instructed becomes meaningless. If both of them are deluded by the illusory energy (māyā), then there is no need of one being the instructor and the other the instructed. Such instruction would be useless because, in the clutches of māyā, no one can be an authoritative instructor. Under the circumstances, it is admitted that Lord Kṛṣṇa is the Supreme Lord, superior in position to the living entity, Arjuna, who is a forgotten soul deluded by māyā.