Chapter 5, Verse 12
Part of 5: Karm Sanyās Yog — कर्मसंन्यासयोगयुक्तः कर्मफलं त्यक्त्वा शान्तिमाप्नोति नैष्ठिकीम्। अयुक्तः कामकारेण फले सक्तो निबध्यते॥
yuktaḥ karma-phalaṁ tyaktvā śhāntim āpnoti naiṣhṭhikīm ayuktaḥ kāma-kāreṇa phale sakto nibadhyate
The one who is united (the well-poised or harmonized) having abandoned the fruit of action attains eternal peace; whereas the one who is not united (the unsteady or unbalanced), impelled by desire and attached to the fruit, is bound.
Santim naishthikim is interpreted as peace born of devotion of steadfastness. The harmonious man who does actions for the sake of the Lord without expectation of the fruit and who says? I do actions for my Lord only, not for my personal gain or profit, attains to the peace born of devotion, through the following four stages, viz., purity of mind, the attainment of knowledge, renunciation of actions, and steadiness in wisdom. But the unbalanced or the unharmonised man who is led by desire and who is attached to the fruits of the actions and who says? I have done such and such an action I will get such and such a fruit, is firmly bound.