2-13

देहिनोऽस्मिन् यथा देहे कौमारम् यौव्वनम् जरा ।
तथा देहान्तरप्राप्तिः धीरस्तत्र न मुह्यति ॥ १३ ॥

dehino'smin yathA dehe kaumAram yauvvanam jarA |
tathA dehAntaraprAptiH dhIrastatra na muhyati || 13 ||

यथा [yathA] Just as देहिनः [dehinaH] the Self, tied in with a body, experiences कौमारम् [kaumAram] infancy, यौव्वनम् [yauvvanam] youth, जरा [jarA] and old age अस्मिन् देहे [asmin dehe] in that body, तथा [tathA] so also देहआन्तरप्राप्तिः [dehaAntaraprAptiH] it obtains another body. धीरः [dhIraH] A wise and steadfast person न मुह्यति [na muhyati] does not get carried away तत्र [tatra] in this matter.

When a person gives up childhood and gets to be a youth in the same body, we reason that the person - his Self - is still the same and don’t grieve that ‘the Self is destroyed’.

In the same way, when the Self is done with one body and gets another one, a wise and steadfast person would reason that it isn’t destroyed. Thus, every Self is ever-lasting and it’s not something to grieve about.

Whenever you are driven by outcomes, you confuse the Self with the environment.

What we must do here is just this. The ever-lasting Self is under the influence of actions it has committed - activities driven by outcomes, performed since beginning-less time. It gets associated with a body due to such influence, which is in-line with those actions. The Self is liberated from entrapment in such bodies by doing activities suited to its body, as prescribed by the Lord - without being driven by outcomes.

Even while working without being driven by outcomes, the organs of its body contact their stimuli - as always. This results in feelings such as warmth and cold, triggering experiences of comfort or discomfort. They must be endured till our duty is done.

This is elaborated in the following Shloka: