The Zohar, Chapter “BaHar (On Mount Sinai),” Item 3: At midnight, a northern wind awakens and a flame of fire comes out of the lower altar, Malchut. Then the gates open and low Dinim, Dinim de Nukva, gather in their holes and that flame walks and wanders, and the gates of the Garden of Eden open. Finally, that flame reaches and divides into several sides of the world and enters under the wings of that rooster, and it calls.
The most special corrections are performed in the state called “night” when a person feels darkness, lack of strength or interest, when spirituality does not attract him much, he is tired, he wants to forget everything and fall asleep, and he is fed up with everything – in short, when he does not feel the importance of the spiritual goal.
The work at “night” is crucial. It is written that King David “got up” at “midnight” and took upon himself the “northern wind,” the great restricting powers of overcoming and correcting egoism (“Gevurot” and “Dinim“). Precisely using these unpleasant “northern” powers he “played the harp” and in this way he welcomed “dawn,” which is the manifestation of the Light in the soul.
During all the work at “night” he was bringing himself to the state where he was turning the very desires (Kelim) in which he sensed darkness, lack of power, and separation from the Creator; he “cried and screamed” into desires or “vessels” for the Light. That brought about “morning.”
In spirituality, there is no morning, evening, or afternoon. We perceive the entire reality within our desire. This is why we reveal the “Light” in our corrected desire which formerly was dark and empty. Then the Light of Hassadim shines in it, and this is called “day.” When the Light of Hassadim cannot shine, meaning we don’t have the intention to bestow, it is called “night.”
From the Evening Zohar Lesson 4/22/10