When you maintain a meditative state for a long time, as a beginner you will have the experiences of bliss, clarity or non-conceptuality, which will mask the face of your true nature.  

So if you free it from this shell of attachment to this experience, and lay bare the actual face of rigpa (natural awareness), then wisdom will shine out from within.  

Therefore the saying:

The more it is disrupted,

The better the meditation of a yogin.

The further it has to drop,

The greater the force of a waterfall.