Quieten the mind

To quiet the mind in such a way that no thoughts will come is not easy and usually takes time. The most necessary thing is to feel a quietude in the mind so that if thoughts come they do not disturb or hold the mind or make it follow them, but simply cross and pass away. The mind first becomes the witness of the passage of thought and not the thinker, afterwards it is able not to watch the thoughts but lets them pass unnoticed and concentrates in itself or on the object it chooses without trouble.

Ref: Letters on Yoga – III