Before using our hands, we must clean them, we use soap and water for this. However, when our hands are covered in soap they are not yet clean, we must rinse it all off. We use one thing to remove other things and then we send it all away.
In meditation the thought of our breath is used to wash away other thoughts. When we reach a meditative state we can rinse away our thought of breath along with all the others. –Based on a teaching of Sri Swami Satchidananda.
Zen Momentum 