According to the Bhagavad Gita, “Samatvam Yoga Uchyate”, is the last line of verse 48, chapter 2. It translates to equanimity is called yoga or evenness is yoga
In the Bhagavad Gita, Lord Krishna defines yoga as Samatvam Yoga Uchyate, which means Samatvam is Yoga.
Lord Krishna explains that samatvam is a balance of mind in success and failure, gain and loss, pleasure, and pain. A yogi should be able to remain equipoised in all circumstances. That is samatvam, the yoga of equanimity, calm, and composure.