यं हि न व्यथयन्त्येते पुरुषं पुरुषर्षभ।
समदुःखसुखं धीरं सोऽमृतत्वाय कल्पते।।2.15।।
O (Arjuna, who are) foremost among men, verily, the person to whom these do not torment, the wise man to whom sukha and dukha are the same, he is fit for Moksha.
What is the benefit to those who bear these cold-heat and sukha-dukha as prescribed?
A person who is equanimous in sukha and dukha i.e. a person who is devoid of harsha and vishada when sukha and dukha are respectively got, such a wise person is not disturbed or perturbed by cold-heat etc as mentioned due to nitya-atma-darshan. Such atma-swaroop-darshan-nishth person goes beyond death and is eligible for moksha.
There is one more reason due to which bearing cold-heat and sukha-dukha without indulging in shoka-moha is logical. [In next shloka]