As in a dream this body (inactive) and the enlivening spirit in its subtile form, separating itself from the former, walks forth, so, in the state called deep sleep (or death), the subtile forin with all the senses becomes inactive, and the Understanding, separated from it, remains awake. The same is the case with Existence and Non-Existence.
मनुरुवाच यथा व्यक्तमिदं शेते स्वप्ने चरति चेतनम्। ज्ञानमिन्द्रियसंयुक्तं तद्वत् प्रेत्य भवाभवौ॥