Bhagavad Gita 6.23

तं विद्याद् दुःखसंयोगवियोगं योगसंज्ञितम्।स निश्चयेन योक्तव्यो योगोऽनिर्विण्णचेतसा ॥६.२३॥

taṃ vidyād duḥkhasaṃyogaviyogaṃ yogasaṃjñitamsa niścayena yoktavyo yogo’nirviṇṇacetasā

Let this be known by the name of Yoga, the severance from union with pain. This Yoga should be practiced with determination and with an undespairing mind.

गीता