“When the body is in a whirlpool, is simply moving, enjoying movement, suddenly you can become aware of the inner witness who is a non-mover, who has never moved, who is the unmoving centre of the moving world. But when the body is in movement you can see it in contrast. Ordinarily we move - we walk, we talk, we take a bath, we go to sleep - but these movements have become routine. When you are in a dance and you go faster and faster and faster, and a moment comes when the movement is no more routine; suddenly you are going absolutely crazy - you become aware of the non-moving inside you. You see your own body moving. You become a witness; you start hovering beyond the body. That's why the Sufis became so interested in the whirling dervish dance. The more you whirl, the easier it is to know the non-moving centre inside you.
So start dancing...

Sufis the People on the path
The Wisdom of the Sands
Unio Mystic vol. 2

Osho talk on CD on the life os s sufi:
Trusting the Inner Guide