'And when (it is said that) there (in the Sushupti) he does not touch, yet he is touching, though he does not touch. For touching is inseparable from the toucher, because it cannot perish. But there is then no second, nothing else different from him that he could think.

In plain words: In deep, dreamless sleep a person touches nothing. Still, the power to feel touch does not die. There is just nothing outside him to touch.