|Chapter 2: Contents of the Gita Summarized|
ya nisa sarva-bhutanam
tasyam jagarti samyami
yasyam jagrati bhutani
sa nisa pasyato muneh
What is night for all beings is the time of awakening for the self-controlled; and the time of awakening for all beings is night for the introspective sage.
In the last four verses Krishna spoke about one who is attached and one who is detached. They have two opposing types of intelligence: that which is directed towards soul and that which is directed towards matter. In this verse, Krishna contrasts the intrinsic nature of these two types of intelligence. He uses the day and night analogy to indicate that the meditation of these two types of people is completely opposite. At night a person who is dreaming is unaware of what is really happening. For instance there may be a fire in the house, or an intruder – but a sleeping person is completely unaware of this reality and is instead focusing on the preceived reality he is experiencing in his dreams. Similarly, materialists, with intelligence directed towards material sense objects, directly realize the happiness, lamentation and bewilderment of those sense objects upon which their intelligence is fixed. For them that is real. The reality of the spiritual nature of the soul is ignored because for them, it simply does not exist. For a spiritualist this is dreaming, since for him these sense objects have no factual reality. For him the reality is the bliss derived on fixing the intelligence on the spiritual aspect of one's existence.
Please read the Sanskrit Verse and the Prabhupada's Purport.