2.15 That person endowed with courage, who considers pain as inevitable as pleasure, and who performs war and such other acts suited to his station in life without attachment to the results and only as a means of attaining immortality - one whom the impact of weapons in war etc., which involve soft or harsh contacts, do not trouble, that person only attains immortality, not a person like you, who cannnot bear grief. As the selves are immortal, what is to be done here, is this much only. This is the meaning.

Because of the immortality of the selves and the natural destructibility of the bodies, there is no cause for grief. It was told (previously):  'The wise grieve neither for the dead nor for the living' (2. 11). Now the Lord elucidates the same view.