Answer: The oral Torah explains the written Torah, which only Kabbalists can understand according to their level of spiritual attainment.
We should know how to read the Torah, and in order to do so, we must learn Hebrew because all of the words are terribly distorted by translation. The letters that make up the word have a very deep meaning: their order, sound, the similarity or difference between them, and so on. Every letter is made of several elements that indicate certain forces of nature, whether positive or negative, that operate horizontally or vertically by drawing toward them or by being distant. This is the reason that writing the letters is a special art.
Eventually, a person begins to understand that there is an encoded description of consecutive spiritual acts before him, not an ordinary text.
In Hebrew, every letter is a symbol, a unique signal with many elements that are connected in a special way and convey information, a bit of concrete information that contains the whole spiritual structure inside it.
It is possible to simply read Kabbalah books, and it is possible to read them in great depth and penetrate the internal meaning. When a person enters the text, he travels through it until he understands everything that happens in it and the flow of the internal information. It is a totally different attainment of the Torah, and this is actually what is called “secret” to a certain degree.
Therefore, the oral Torah is the Torah that is forbidden to be taught. The concept of forbidden refers to the fact that it is impossible since a person will understand nothing before he is a Kabbalist. On the other hand, there is no need to understand anything in the wisdom of Kabbalah. In the wisdom of Kabbalah, everything is allowed—everything is for a person, for his sake.
From the Kabbalah Lesson in Russian 9/4/16