2.13 As the self is eternal, one does not grieve, thinking that the self is lost, when an embodied self living in a body gives up the state of childhood and attains youth and other states. Similarly, the wise men, knowing that the self is eternal, do not grieve, when the self attains a body different from the present body. Hence the selves, being eternal, are not fit objects for grief.

This much has to be done here; the eternal selves because of Their being subject ot beginningless Karma become endowed with bodies suited to Their Karmas. To get rid of this bondage (of bodies), embodied beings perform duties like war appropriate to their stations in life with the help of the same bodies in an attitude of detachment from the fruits as prescribed by the scripture. Even to such aspirants, contacts with sense-objects give pleasure and pain, arising from cold, heat and such other things. But these experiences are to be endured till the acts enjoined in the scriptures come to an end.

The Lord explains the significance immediately afterwards: