Bhagavad Gita 18.49असक्तबुद्धिः सर्वत्र जितात्मा विगतस्पृहः।नैष्कर्म्यसिद्धिं परमां संन्यासेनाधिगच्छति ॥

The mind of one who is free from attachment to wife, son, body and property, who has controlled his senses and the mind, who has no desire for the body, for life and for sensual pleasure, turns inwards towards God or the immortal Self. It is not attracted by the sensual objects of the world. It is filled with dispassion and discrimination.He gradually gets himself established in his own Self which is of the nature of ExistenceKnowledgeBliss. Such a person who has knowledge of the Self attains to the highest perfection, to pefect freedom from action by renunciation.Ignorance is destroyed by the attainment of the knowledge of the Self. There is cessation of activity. One may perform actions for the solidarity of the world and yet he will not be bound by actions as he has attained absolute freedom from action through the knowledge of the Self. The fire of knowledge has burnt the fruitbearing effects of Karmas or actions. He has no idea of agency as he is absolutely free from egoism, as he has identified himself with the Supreme Being.Naishkarmya siddhi may also mean the attainment of the state of Naishkarmya. In this exalted, magnanimous, ineffable state of divine splendour and glory, one remains as the actionless Self. This is the state of immediate liberation of the Vedantins (Kaivalya Moksha or Sadyomukti)