Verse
तं विद्याद् दुःखसंयोगव् इयोगं योगसंज्ञितम् ।स निश्चयेन योक्तव्यो योगोऽनिर्विण्णचेतसा ॥
It is the putting away of the contact with pain, the divorce of the mind’s marriage with grief. The firm winning of this inalienable spiritual bliss is Yoga; it is the divine union. This Yoga is to be resolutely practised without yielding to any discouragement by difficulty or failure (until the release, until the bliss of Nirvana is secured as an eternal possession).
Gītā 6·23