Arjuna then asked Krishna to describe one of stable consciousness (Sthitha Pragnya) and one who is in Samadhi. Sri Krishna then said that a steady man is one who delights in his Self and who has given up all desires of the mind. His mind is not agitated in sorrow and he is untouched by comforts. He is free from attachment, anger and fear. He has no liking for anything and is neither happy nor sad on getting good or bad things. He withdraws his senses from the sense objects (matter), as a turtle into its shell. The sense objects fall off from such a withdrawn person but not the liking for them. Even that liking for them falls off when he realizes that supreme being. The senses draw even the mind of a wise person even though he tries to overcome them. He who controls his senses and sits meditating on Krishna, is a person of steady wisdom.
A person develops attachment to sense-objects that he thinks about. From attachment springs desire and from desire springs anger. Delusion springs from anger and from delusion, confusion of memory. That leads to the destruction of intelligence and from that person is destroyed.
A self-controlled person can move amidst sense objects free from attachment and aversion. He attains serenity. This results in the destruction of his misery. He becomes steady soon.
An uncontrolled person has neither knowledge, nor meditation, nor peace nor happiness. His mind follows his senses. Therefore a man of controlled senses is steady. That which is night to other is day to him and that which is day to others is night to him who sees.
Even as an ocean is unchanging though all rivers enter it, a man who is unaffected by the sense-objects that enter him attains peace. He who is detached from the sense objects, devoid of the idea of ownership and is free from egoism attains peace.
This is the Brahmi State. One who attains this is not deluded and if he remains in this state at death he attains Brahma Nirvanam.
Note: Brahma (the great) is the creator of the Universe. His Maya (illusion) is the physics of this universe. If you are not deluded by Brahma Maya, you can attain Brahma Padam or the state of Brahma. Vishnu Maya is greater than Brahma Maya. Krishna is an Avatar (or descent) of Vishnu and capable of Vishnu Maya. Therefore, the miracles of Krishna.
Source: The Bhagavad Gita (Complete)