In the fourth question the disciple had asked the Rishi about the Core of Existence, the Truth or the Reality which is behind the individual and the cosmos. As the student proceeded with the question, the Master said that it is absolutely necessary for an individual to experience the feelings of dream as well as deep sleep. In this section the student had asked that how exactly the ego-centre functions in the deep sleep state of human beings. With the help of this section one is able to get insights of various personalities of an individual, in the state of waking, in the state of dream and in the state of deep sleep.

The question which was posed by Gargya, the grandson of Surya to the Master was `O Bhagavan! Which are they (the organs) that sleep in man? Which, again, are awake in him? Which is the Devata (organ) who sees the dream? Whose is this happiness? On which do all these indeed depend?`

Through these questions the disciple is desirous of knowing as to who is the guardian who continues his function even when the sleeper has withdrawn his consciousness into the mind.

As the state of a waker and a dreamer is completely different it is very natural that the student will have the urge to know about the exact nature and the structure of dreamer within an individual and hence he reaches the feet of the Rishi with the question. In fact it can be said that the student is interested in knowing more about the substratum within each individual in the three different ego centers that are functioning within an individual. It can be said that the central theme of the question was to find out the conscious factor, the divine spark and the life centre.

When the Guru had started answering he had said that in the waking state the sense organs are fully active in the physical structure of the individuals. Regarding the sleep state he had said that it is not the waking state and during this time all the indriyas or the sense organs retire into the source of the mind. Rishi Pippalada had said that during the sleep state the entire world of plurality realised by the five sense organs of our physical structure become one in the Deva or in the Mind. The Rishi had gone further in his explanation, he had said that during the deep sleep state the mind does not undergo the any kind of annihilation or destruction, only for a temporary period of time, the mind goes under the veil of self-forgetfulness and ignorance.

The second question of the student was about all those faculties which were continually working within the physical structure of the individual without even being aware of the physical body of the individual. To this the Rishi had answered that only the Prana or the Vital Air is active within the body of a sleeping man. As the Rishi tries to make his disciple aware of the awakened state of the Prana he at the same time also tried to initiate his student into a process of meditation.

In this section of the Prashnopanisad the Master had said that it is the udana which leads the dreamer and the waker and finally initiates him into the state of sleep.

After Rishi Pippalada had described the sleep condition and had explained the various centers of energy that continuously guards the state of sleeper, the Rishi had started explaining the third query of the student which was `What is the Deva who sees the dream?`

As the Guru tried to answer this query he had explained the relation between the dreamer and the dreamt in the conscious state. He had said that the mind does not roam essentially into the challenges suggested by the sense organs but it also perceives many things which are completely impressions which are created by the mind itself. Rather the Master wanted to say that dreams are impressions left by the subconscious ideas. According to the Guru, the dream state takes place when the individual gets fatigued with the plurality of the physical world around him and is influenced by the plurality of the world that has been created by his own mind. During the dream state, the individual is no more conscious of his physical body but is very much conscious about his dream body.

The Master had told his disciple that when the Supreme Reality or the life source functions in the body and expresses itself through the sense organs it becomes the state of waking but when this Supreme Reality functions through the mind and the intellect it becomes the dreamer personality. Rather it could be said that when the mind is dropped, a blissful state rises within the individual and within the Sleeper raises the Lord and the Master.

The Rishi had explained that when the mind withdraws from dreams it comes closer to the all encompassing light or the transcendental light and in the state of the sleeper the mind is blinded by the light of the Atman. He had said that during the state of sleep as the mind is close to the Atman, an individual experiences negative bliss. It is termed as negative bliss because there is absence of any physical or intellectual commotions.

It can be summarized that in the state of sleep, the ego-center gets drowned in a mist of ignorance and consequently a state of unknown bliss can be experienced by an individual. This is because during the state of sleep, not only the organs of knowledge and actions retire into inaction but at the same time the actions of perception and thought also stops functioning. During the sleeping state it is only the Prana which functions as the guardian angel.

Towards the end of this section, the Rishi had said that discovery of the Truth should be the mission of human life. Discovery of the Truth is possible when an individual is able to sublimate the ego in him becomes on annihilating the ego and individual becomes aware of the `awareness` that is present in him. This is because Awareness is omniscient. He had told his pupil that a man who realises that his entity is far beyond an ego-centric self and understands that the essence of his existence is the True Self or the Atman, only such an individual is able to achieve unity with the divine and in turn is able to experience the Absolute Bliss.