Likutei Moharan 24:8/ליקוטי מוהר"ן כ״ד:ח׳

18. When a person creates and properly rectifies the controls/ Keter, and the mentalities race to grasp the Light of the Infinite One but the Keter restrains the intellect in order to compose it—then, as a result of the racing and restraining, the mentalities strike the controls, creating chambers for the Light of the Infinite One. Nevertheless, [these chambers] are neither known nor make themselves known.

2As is brought in the Zohar, the Portion of Noach (I, 65a): “And from inside this curtain, through the chasing of the [upper] thought that reaches and does not reach”—the curtain being the controls/ Keter, which is spread out between the creation and the Creator—“Nine Chambers are created. They are neither [from the level of] lights nor spirits nor upper souls. There is no one who can comprehend them… they do not make themselves attainable or known.”

3And know! this is the culmination of knowledge. For the culmination of all knowledge [of God] is when one realizes that one knows nothing.

4This is the meaning of (Isaiah 58:11), “He will satiate your soul with splendors.” For these lights are the Splendors, they are higher than the sefirot. Fortunate is he who is worthy of having his mind race to grasp these insights—even though it is not within the power of the intellect to attain them, for “they do not make themselves attainable or known.”

5As for these Nine Chambers, they are created as a result of the collision that occurs when the mentalities collide with the Keter while racing. The mentalities are three, and each one is comprised of three because they become encompassed [in each other] while racing. And three times three equals nine. This is the Nine Chambers.