मात्रास्पर्शास्तु कौन्तेय शीतोष्णसुखदुःखदाः । आगमापायिनोऽनित्यास्तांस्तितिक्षस्व भारत ॥
Transliteration
matra-sparsas tu kaunteya sitosna-sukha-duhkha-dah agamapayino 'nityas tams titiksasva bharata
Translation
The contact of senses with their objects, O Son of Kunti, give rise to feelings of cold and heat, pleasure and pain. They come and go, they are impermanent, endure them, O Arjuna.
Purport
After explaining the continuity of life to Arjuna in short, merciful Supreme Lord Bhagvan Shri Krishna explains the grieving Arjuna about the secret of happiness and sorrow. Bhagvan said that feeling happiness, sadness is similar in nature as feeling of hot and cold, as it too arise by the interaction of physical body with external environment and the effects hence caused.