Nisargadatta: As long as you are a beginner certain formalised meditations, or prayers may be good for you. But for a seeker for reality there is only one meditation -- the rigorous refusal to harbour thoughts. To be free from thoughts is itself meditation.
Questioner: How is it done?
Nisargadatta: You begin by letting thoughts flow and watching them. The very observation slows down the mind till it stops altogether. Once the mind is quiet, keep it quiet. Don't get bored with peace, be in it, go deeper into it.
Questioner: I heard of holding on to one thought in order to keep other thoughts away. But how to keep all thoughts away? The very idea is also a thought.
Nisargadatta: Experiment anew, don't go by past experience. Watch your thoughts and watch yourself watching the thoughts. The state of freedom from all thoughts will happen suddenly and by the bliss of it you shall recognise it.
Extract from the book I AM THAT Ch. 48