Bhagavad Gita 12.18

He to whom friend and foe are alike, who welcomes equally honor and dishonor, heat and cold, pleasure and pain, and who is enamored of nothing—

समः शत्रौ च मित्रे च तथा मानापमानयोः।शीतोष्णसुखदुःखेषु समः सङ्गविवर्जितः॥

samaḥ śatrau ca mitre ca tathā mānāpamānayoḥ|śītoṣṇasukhaduḥkheṣu samaḥ saṅgavivarjitaḥ||

English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).