First, meditation should be of a negative nature. Think away everything. Analyse everything that comes in the mind by the sheer action of the will.
Next, assert what we really are–existence, knowledge, and bliss–being, knowing, and loving.
Meditation is the means of unification of the subject and object. Meditate:
Above, it is full of me; below, it is full of me; in the middle, it is full of me. I am in all beings, and all beings are in me. Om Tat Sat, I am It. I am existence above mind. I and the one spirit of the universe. I am neither pleasure nor pain.
The body drinks, eats, and so on. I am not the body. I am not mind. I am He.
I am the witness. I look on. When health comes I am the witness. When disease comes I am the witness.
I am Existence, Knowledge, Bliss.
I am the essence and nectar of knowledge. Through eternity I change not. I am calm, resplendent, and unchanging.
(CW. Vol.6- Page 91)