Likutei Moharan 234:2/ליקוטי מוהר"ן רל״ד:ב׳

12. One also has to know how to tell the story, because in each story there is restriction. In addition, when a person wants to purify his mind by telling a story about the tzaddik, then the story and the telling, which is speech, become thought for him. And certainly this tzaddik about whom he tells must be greater than himself, so that for him the stories about this tzaddik are in the aspect of thought. He must therefore know of whom to tell and how to tell.

2Then, his mind is purified and he can ascend to the World of Thought. This is called elevating the worlds.

3For thought is very exalted, and someone who wants to enter the World of Thought must remain silent. Even if he speaks proper words at that moment, he loses the thought. This is because thought is a very exalted thing, which even proper words can nullify. This is the aspect of “Be silent! This is the way it has arisen in thought” (Menachot 29b)—to ascend to thought one must be silent. Even with being silent, not speaking at all, there are nonetheless disturbances that confuse thought and distract it. This is why purifying the mind is necessary, and this is achieved through storytelling, as explained above.