This is the known concept, that in order for a level to extend downward and descend from one level to the next, it is specifically through the power of a level that transcends it.
To understand this well, we must understand what is written about King Shlomo, “And he spoke three thousand analogies.” (Melachim I, 5:12)
The idea of the 3,000 analogies is: We see, that a wise man, despite knowing wise ideas himself, nonetheless, he is not yet able to explain this wisdom to another person, unless, before he explains it, he first strongly connects his mind to that concept, in order to settle his thoughts, to the point where he can determine how and in what way he can explain and bring down in more earthly terms and explain by way of analogies. Meaning, he needs to be able to find the same essential concept even as it is expressed in physical matters.
But for this, one must be an extraordinarily wise person, in order to express his wisdom also in mundane terms which are lower than how these lofty ideas originally existed in abstraction in himself, i.e., in his mind. Only King Shlomo a”h, with his great understanding, was able to find 3,000 analogies, meaning that even at a distance of 3,000 levels of wisdom lower than how this knowledge existed in himself, even there he was able to find and show this particular wise idea itself, which Shlomo knew.
For example: Imagine a great kabbalist and sage, who understands very lofty spiritual ideas. He gathers school children, less than 13 years old, to speak with them. He explains to them the same lofty ideas that he understands, in the language and level of understanding of young children. In order to do this, he must connect to those spiritual concepts so strongly, on such an essential level, that he is able to see these concepts everywhere, even as they are relevant in the physical life of child. The level of understanding of the children was thousands of times lower than his level of understanding, yet he is able to see that concept as it exists in their level. (This is something that the Lubavitcher Rebbe did every time he spoke with children, which was several times a year, especially from 1981-1992.)
Therefore, when it is necessary to bring that level of wisdom down, so that his understanding should expansive enough to find itself in a very different level, the power behind this must come from a source much higher than Chochma, and only then, when this lofty source is expressed, can there be revealed this expansive level of Bina-Understanding. However, from only Chochma itself, it is not possible that there should come from it that expansive Bina-Understanding. Rather, the root of Bina and its ability of revelation is powered by the revelation of Atik; because of it and through it, Bina comes down and becomes expansively revealed.
