The Zohar, Chapter Bo (Come Unto Pharaoh), Item 63: There is a great and peaceful river. And because its Bina, Tifferet, and Malchut fell into Keter and Hochma of the small rivers during the small state (Katnut), when the big state (Gadlut) comes and the peaceful river once more elevates its Bina, Tifferet and Malchut to itself, Keter and Hochma of the small rivers ascend with them and receive GAR from it.
There is a great and peaceful river, which is connected to all the small rivers through their Galgalta ve Eynaim. This great river cancels its AHP (which is why it is called peaceful) in order to give the smaller ones the opportunity to connect to it. It waits for them to connect to it, and as soon as they do, it begins to elevate them together with itself. That is how they ascend from their degree onto the next. And at the higher degree there is another “peaceful river,” and they connect to it and ascend further still. That is how the “spiritual elevator” operates.
Everything that appears as darkness to us is in fact Light in the state of concealment. There is no darkness; the only reason we see darkness is because we relate to Light egoistically. This is why it hides from us, and shines upon us from the reverse side. That is why the word Ohr in Hebrew means “Light,” while in Aramaic a similar word, Ohrta, means “night.” These two languages are opposite to one another like two sides of a coin.
In fact, there is no darkness. It exists only with respect to our uncorrected desires, but darkness is entirely absent when one’s desires are corrected. Therefore, whenever we feel a lack of inspiration or a bad mood, it means we are being given the opportunity to awaken to a greater degree of connection with the Upper One. This connection can be attained precisely through the darkness that we presently feel.