The beginning of the explanations of the three inner Sephiroth are touched on here. Kether is not included because it is so much a part of the Mystery that we cannot begin to explain its essence and are left with what we can explain as we see below.
Bahir 127. Why are there three "holies" and not four? Because the holiness on high is three by three. It is thus written, "God is King, God was King, God will be King forever and ever." It is also written (Numbers 6:24-26) , "May God bless you... May God shine upon you... May God lift..." It is furthermore written (Exodus 34:6), "God (YHVH), God (YHVH). " The third one includes the rest of God's Attributes. What are they? [As the verse continues], "God, merciful and gracious" & the thirteen Attributes [of Mercy
The three form the triangle of Chokmah, Binah and Daas configured on the tree as its upper most inner triangle. It is the seat of ideation. These three indicate the three considerations that every thought goes through as it becomes known to you. First there is the initial flash of inspiration or Chokmah The uniqueness of a thought is enough to completely charge the entire system as it considers (Binah) what to do with this thought in terms of what direction will the energy flow from and to. Then there is the identification of the self with this now fleshed out concept. Here is where you make it a part of you and have an emotional connection to this. When you make it your own and begin to realize it everywhere in your life you experience what is called (Daas). Notice that these emotional qualities are all descending from what is called Mercy above.
That initial idea, that spark you and the sense that now you have it is Chokmah. In Chokmah however all you have is the sense of the idea. You do not have its explanation nor can you explain it yet.
Then you begin thinking about this idea and add thoughts to it building up a superstructure inside of intellectual meaning and connection. This is called Binah. Finally you see an example of this idea occuring in your life and then you relate this experience to the idea. This is Daas. You bond with Daas in order to make this idea once and for all your own.
Compare now the flow of thought through these first three Sephiroth. You are thirsty then you discover the faucet and know that there is water that will come out of this pipeline. You are saved but have not taken a drop to assuage your thirst. If you walk away from the faucet at this time you will continue to be thirsty. Now you take a cup (Binah) and fill it with water making the idea into a practical useable form. At last you drink the water making it a part of you, (Daas).
It is important to notice how we have explained these three Sephiroth because in our explanation we have used the same process as that which is being explained. Wrap you mind around this and then watch how the flow of ideas takes place in your life and apply these three thought-forms to your experiences. We're flowing now and will continue to do so as we enter more deeply into the realm of these flowing spheres of ideation.