यं हि न व्यथयन्त्येते पुरुषं पुरुषर्षभ।
समदुःखसुखं धीरं सोऽमृतत्वाय कल्पते।।2.15।।
O (Arjuna, who are) foremost among men, verily, the person whom these do not torment, the wise man to whom sorrow and happhiness are the same he is fit for Immortality.
What is the benefit to those who bear these cold-heat and sukha-dukha as prescribed?
One who bears cold-heat and sukha-dukha and is not disturbed or perturbed by them due to being always established in his Self goes beyond death and is eligible for moksha.
There is one more reason due to which one should bear cold-heat and such-dukha without indulging in shoka-moha. [In next shloka]