Concentration is not thinking of one thing. On the contrary, it is excluding all thoughts, since all thoughts obstruct the sense of one's true being. All efforts are to be directed simply to removing the veil of ignorance. Concentrating the mind solely on the Self will lead to happiness or bliss. Drawing in the thoughts, restraining them and preventing them from straying outwards is called detachment (vairagya). Fixing them in the Self is spiritual practice (sadhana). Concentrating on the heart is the same as concentrating on the Self. Heart is another name for Self.
Ramana MaharshiWhat is illusion? M.: To whom is the illusion? Find it out. Then illusion will vanish. Generally people want to know about illusion and do not examine to whom it is. It is foolish. Illusion is outside and unknown. But the seeker is considered to be known and is inside. Find out what is immediate, intimate, instead of trying to find out what is distant and unknown.
Ramana MaharshiSee what helps you to keep away all other thoughts and adopt that method for your meditation.
Ramana MaharshiThe thing to do is to concentrate on the seer and not on the seen, not on the objects, but on the Light which reveals them.
Ramana MaharshiConcentration of the mind is in a way common to both Knowledge and Yoga. Yoga aims at union of the individual with the universal, the Reality. This Reality cannot be new. It must exist even now, and it does exist.
Ramana MaharshiEvery living being longs always to be happy, untainted by sorrow; and everyone has the greatest love for himself, which is solely due to the fact that happiness is his real nature. Hence, in order to realize that inherent and untainted happiness, which indeed he daily experiences when the mind is subdued in deep sleep, it is essential that he should know himself. For obtaining such knowledge the inquiry 'Who am I?' in quest of the Self is the best means.
Ramana Maharshi