Bhagavad Gita: Verse 2.15
यं हि न व्यथयन्त्येते पुरुषं पुरुषर्षभ ।
समदुःखसुखं धीरं सोऽमृतत्वाय कल्पते ॥ २-१५॥
yaṃ hi na vyathayantyete puruṣaṃ puruṣarṣabha
samaduḥkhasukhaṃ dhīraṃ so’mṛtatvāya kalpate
That firm man whom, surely, these afflict not, O chief among men, to whom pleasure and pain are the same, is fit for realising the Immortality of the Self.
yaṃ = one to whom; hi = certainly; na = never; vyathayanti = are distressing; ete = all these; puruṣaṃ = to a person; puruṣarṣabha = O best among men; sama = unaltered; duḥkha = in distress; sukhaṃ = and happiness; dhīraṃ = patient; saḥ = he; amṛtattvāya = for liberation; kalpate = is considered eligible.;