The 'I'-thought which rises in this manner [by catching hold of something] appears in the form of the three gunas, and of these three the rajas and tamas aspects cling to and identify with the body. The remaining one, which is pure sattva, is alone the natural characteristic of the mind, and this stands clinging to the reality. However, in the pure sattvic state, the 'I'-thought is no longer really a thought, it is the Heart itself… The state in which the pure sattva mind shines clinging to the Self is called aham sphurana…The source to which this sphurana clings alone is called the reality or pure consciousness… When the mind, having pure sattva as its characteristic, remain attending to the aham sphurana, which is the sign of the forthcoming direct experience of the Self, the downward-facing Heart becomes upward-facing and remains in the form of That. This aforesaid attention to the source of the aham sphurana alone is the path. When thus attended to, Self, the reality, alone will remain shining in the centre of the Heart as I-am-I.

-Sri Ramana in a letter to Ganapathi Muni