When a person attains the revelation of the true nature and reveals an inner vision, he starts to see one more reality inside of him in addition to the one he felt before. He perceives this new reality more intensely than our current one, and feels that it determines what happens in our reality.
Therefore, he calls this new reality that he has revealed, “the upper world.” This is a world of forces that becomes revealed to him. These forces, which act inside of his desire, bring him all kinds of experiences and impressions, depicting different forms and pictures inside of him. But he does not know what to call these forces, how to describe them, and how to talk about them.
After all, if he experiences a new sensation that has no connection with his entire past, then it’s unclear what to call it. But then he reveals the connection between these new sensations and the pictures that they project on the lowest screen that depicts this world to us.
He discovers that every force he reveals, every sensation in the upper world has its own result on the picture we see here, in the lower world. It’s as if every object or action of this world has its own force standing behind it, which supports him, manipulates him, and drives him.
He is left with just one way to explain the upper world—by taking names from this lower world for this purpose. This language is called “the language of branches.” Now, a person who is in the sensation of the upper world can talk about what he feels! He has names for every force, every spiritual action, every spiritual essence according to the results of these forces, which they depict and create for us in this world.
From the 1st part of the Daily Kabbalah Lesson 7/22/11, Writings of Rabash