Bhagavad Gita · Chapter 2: The Path of Understanding
Bhagavad Gita 2.14
मात्रास्पर्शास्तु कौन्तेय शीतोष्णसुखदुःखदाः ।
आगमापायिनोऽनित्यास्तांस्तितिक्षस्व भारत ॥
mātrāsparśāstu kaunteya śītoṣṇasukhaduḥkhadāḥ | āgamāpāyino'nityāstāṃstitikṣasva bhārata ||
The contacts of the senses with their objects, Arjuna, bring cold and heat, pleasure and pain. They come and go and do not last. Endure them.
Modern context
Pleasant and unpleasant sensations arrive like the seasons, and like the seasons they leave. Nobody takes winter personally. Krishna asks for the same attitude towards discomfort and delight: feel them fully, know they will pass, and do not let either one make your decisions.