BRAHMAN
8. In the interior of the Heart-cave (there) shines alone the One Brahman as the ‘I-I’, verily the self-conscious Atman. Realize that State of steadfast inherence in the Self, entering into the Heart either by diving deep within through Self-enquiry ; or by submergence of the mind (in the Self) through breath-control.
Verse 8 of Supplement to “Truth Revealed –Sad-Vidya” by Sri Ramana Maharshi