At first glance this Iyun is what is called the deep concentration of the mind in the language of the world, but it is not so since the concentration of the mind is just a vessel to come to the depths of the thing actually (as it is). That is, the contemplative or meditative concentration is only a vessel to get to the depth of a subject. Whereas the Iyun of Binah, that is, intensive analytical explanatory study is the vessel to the actual subject itself.
And higher than this is the level of Daas/Concentration called a Ma'amik (deep delver) who reaches higher than even the wisdom itself. Even though the Chochmah is in the aspect of being the actual Ein (nothing) (non-apprehended ethereal source) of the concept before it came to be include in the depth of the point of the Musag of Binah (the idea as it is intellectually grasped by understanding). Like a spring in regards to a river as stated above. But the aspect of going deep into the root of the idea, the root of this (aspect) reaches into the root which brings forth the flowing of the spring of Chochmah etc. and is called the depths of Chochmah or the hidden places of Chochmah.
And Now Chapter 1.10
Now to explain the dimensions of Chochmah itself.
For just as there are a depth, length and width within Binah, -which is termed a ‘something’ as mentioned previously. So too there is a depth, length and width within the ‘wellspring’ of Chochmah, which is termed a ‘nothing’(relative to Binah). So that, just as a river has three dimensions, so too a wellspring has three dimensions, only that the wellspring compared to the great size of a river is considered like nothing. None the less it has three dimension of its own, only in a smaller scale.
The depth of a wellspring is its original source were it is rooted in the depths of the earth. This source is like a large underground lake and is called an aquifer. These aquifers form as water seeps down through the ground until it comes to collect in large pockets. These then become the source of wells and natural springs. In addition, the deeper the source of a spring is the purer the water will be, because it is filtered as it passes through the rocks, gravel and sand until it reaches the aquifer. On the way down it also collects minerals from the rocks becoming the latest bottled mountain spring mineral water (only $1.99 a bottle). It is from this source that the water spreads upward through the underground channels, until it pushes through the ground and comes, drop by drop, into revelation from its previous hiddenness in the ground’s depths. Its most utter concealment being its utmost depth below, as per "the wellsprings of the abyss burst forth." For the earth is riddled with veins of water, which have a first depth from where the water originates, the aquifer.
It is about this inner depth hidden in the bowels of the earth's crust that it says that ‘Chochmah comes out from nothingness,’ meaning from the hidden aspect of Chochmah that is called the depth of Chochmah.