Don't contemplate as mere activity.
Be void contemplating void.
Once one understands that the ultimate nature of this existence is void, one understands that to be void is the only true mode of meditation.
Notice that void is not the object of meditation. To pair meditator and object creates a dualistic relationship between self and environment that leads one astray.
In meditation we are searching for unity. We need something that takes us out of the normal dualistic modes that are the origins of all our difficulties. Therefore, the only true meditation is one that does not put us into a relationship of viewer and object. Any object, no matter how holy, still reinforces the illusion that there is a reality outside of ourselves. What we are trying to gain is the true interior view: There is no difference between our inner and outer realities.
The ultimate meditation is the realization that we ourselves are empty of distinctions, that our sense of identity is only the result of dualistic clinging. Along with that, we should understand that there is really nothing to contemplate, nothing to think about.
Taken from : Tao: Daily Meditations