Bhagavad Gita 2.15
यं हि न व्यथयन्त्येते पुरुषं पुरुषर्षभ । समदुःखसुखं धीरं सोऽमृतत्वाय कल्पते ॥
yaṃ hi na vyathayanty ete puruṣaṃ puruṣarṣabha | sama-duḥkha-sukhaṃ dhīraṃ so 'mṛtatvāya kalpate ||
Translation
O bull among men, the steady one whom these do not afflict, who is the same in pleasure and pain, is fit for immortality.
Reflection
When did you last let a swing of mood pass through without making it mean something?
Read this verse in its chapter: Chapter Two
The promise attached to 2.14. The person whom the weather no longer rattles, who meets sukha and duḥkha with the same face, is the one ready for amṛtatva, the deathless. Kalpate. Becomes fit for. Not "earns." Not "is granted." Made ready. The structural point: immortality here is not a reward placed somewhere ahead. It is a fitness developed in the way you meet the ordinary alternations of a day. Heat and cold. Praise and blame. Each moment of staying with what is, instead of reacting to its mood, builds the readiness Krishna will spend the rest of the chapter describing.