He [Al-Sadiq] said: "From the aspect of purity. Do you not know that Light does not mix with darkness, nor darkness with light? Do you know their meaning?" I said: "No, my Master." He said: "Their bodies and spirits are one in praise, knowledge, acceptance, and the ultimate end. There was only a difference between them before Tawhid (unification); once they unified, they became one praised entity."

I say: Because when the believer reaches purity, the Dark Veil is lifted from him. He then sees this night—symbolized by Ghayba (Occultation)—as day. Likewise, he sees this day—symbolized by Zuhur (Manifestation)—as night relative to the intensity of the brilliance of his spiritual day.

This is supported by what Al-Sayyid al-Makzun said in his poetry:

A full moon, then the rising of the sun when It appeared from His blaze in the shade of beauty.

Know that this fluctuation is from the perspective of the observer toward the Exalted—whether the observer is luminous or human—as Al-Sayyid al-Makzun (may Allah sanctify him) indicated in his verse, saying: