Ramana Maharshi - Meditation on the Pranav

Question : What is the purport of the teaching that in pratyahara one should meditate on the pranava?
Ramana Maharshi : The purport of prescribing meditation on the pranava is this. The pranava is Omkara consisting of three and a half matras, viz., a, u, m, and ardha-matra. of these, a stands for the waking state, Visva-jiva, and the gross body; u stands for the dream-state Taijasa-jiva, and the subtle body; m stands for the sleep-state, Prajnajiva and the causal body; the ardha-matra represents the Turiya which is the self or ‘I’-nature; and what is beyond that is the state of Turiyatita, or pure Bliss.

The fourth state which is the state of ‘I’-nature was referred to in the section on meditation (dhyana): this has been variously described - as of the nature of amatra which includes the three matras, a, u, and m; as maunakshara (silence syllable); as ajapa (as muttering without muttering) and as the Advaita mantra which is the essence of all mantras such as panchakshara.

In order to get at this true significance, one should meditate on the pranava. This is meditation which is of the nature of devotion consisting in reflection on the truth of the Self. The fruition of this process is samadhi which yields release which is the state of unsurpassed bliss. The revered Gurus also have said that release is to be gained only by devotion which is of the nature of reflection on the truth of the Self.