2.14
मात्रास्पर्शास्तु कौन्तेय शीतोष्णसुखदुःखदाः | आगमापायिनोऽनित्यास्तांस्तितिक्षस्व भारत ||१४||
mātrā-sparśhās tu kaunteya śhītoṣhṇa-sukha-duḥkha-dāḥ āgamāpāyino'nityās tāṁs titikṣhasva bhārata
Translation
O son of Kunti, the contacts of the senses with their objects give rise to cold, heat, pleasure, and pain. They come and go; they are impermanent. Endure them, O Arjuna.
Interpretation
Pleasure and pain, heat and cold — these are the experiences of contact between senses and the external world. They are 'anitya' (impermanent) — they come and go. The practice Krishna recommends is 'titiksha': the capacity to endure without being disturbed. This is not indifference but equanimity — maintaining one's center despite the swings of experience.