Looking through the first five sources of the sheet, we find the following interelated concepts which we are using to build the framework to understanding Tefillin:
Holidays/Shabbat = Tov/Goodness = Direct and intense light, sunlight = Tefillin Shel Rosh.
Chol Ha'moed = (lack of Tov) = Indirect light, moonlight = Tefillin Shel Yad.
We also have G-d wearing Tefillin and us wearing Tefillin. When His Tefillin manifests in this world on habbat, the holidays and Chol Ha'Moed (these are days that express Keter), we remove our own Tefillin.
1) A relationship structure begins to take form in which G-d wears Tefillin that written in them are the praises of Yisrael and we wear our Tefillin that have his praises written in them. And through this mutual feeling of wearing the other's praise, we create a unique relationship.
Relationship requires that I find pride and elevation specifically by sharing my perception and sensation of existence with another. But sharing here means allowing my perception to be informed and filtered through that other. Tefillin are the expression of a glorification and elevation of self through this mechanism. When I allow myself to be defined not just by myself, but also through the perception and creativity of another, I become elevated. That is why the Tefillin are an external object that I bind to myself.
But the elevation of self is dependent on who it is that I relate to. By choosing G-d, and by Him choosing us, as we will see later, we guarantee the Tefillin experience, i.e. an elevated experience through relationship. Being in this type of relationship with the wrong person can be damaging and ruinous.
So the first thing we need to understand in order to get to the depth of our initial points is to see Tefillin as an expression of the elevation and transcedence of the individual self through a mechanism of relationship that allows the self to be defined and shaped through a perception of reality external to the self.
2) The next concept to develop is the sun/moon relationship, which in our context is being expressed as the Tefillin Shel Rosh (head Tefillin) and Tefillin Shel Yad (arm Tefillin).
There is ambivalence as to whether the two Tefillin's are one Mitzvah or two. This ambivalence will play out when we look deeper into the connection and relationship between them. However, let's describe the sun/moon issue.
The difference between the sun and the moon is that the sun affects earth through direct sunlight, whereas the moon affects us through its indirect manipulation of biological cycles. We look at this as a direct light versus a diffused light.
We notice that this marks a great distinction between men and women. More loosely, women tend to educate their children through diffusion and osmosis, where the nuance of life and education are learnt organically and through the setup of the child's environment within the home and without (to the extent that the parent is able to influence, obviously there are many influences in a child's life that are beyond the control of the parent). By contrast, Men tend to teach through direct lesson. (There are many circumstantial influences to this phenomenon. For example, men tend to be out of the house far more than women. Therefore, they don't have the time to teach by example - one of the beautiful things about Shabbat forcing the man to be around the house).
However, more archetypically, men go about life by trying to assert their ideas about the way things ought to be. Women, on the other hand, go about life focusing on the way things currently are. Therefore, a women's modality of thought tends to be almost entirely environment/periphery oriented. A man, though, is more concerned with forging new paths and bringing forth the light of his grand plans. Clearly a perfect parallel to the sun/moon metaphor. (Historically, it has been documented that women's menstruation was regulated by the moon's cycle. The fact that nowadays it is regulated by friends is not far off of this idea either).
What is the sun/moon that exists within an individual man wearing Tefillin (the head one is the sun, and the arm is the moon)?
We look at this through the Mishnaic teaching (Avot, ch. 1) "Say a little, Do a lot".
The sun of the man is his thoughts and his thoughts are expressed as sunlight through his speech. A man's action, acting out his plans, is the relatively soft diffusion of his ideas. Actions are certainly direct, however they are far more responsive and delimited by environmental factos. Speech is "free" and anything can be said, similar to how anything can be imagined. Action, on the other hand, is filtered and directed in many ways through the surrounding environment. Therefore, action cushions and diffuses the intense light of the male plans and perceptions.
In terms of Tefillin, it is clear that the head Tefillin reflect our mind's ideas and that the arm Tefillin reflect our action (there are many many sources for this). By wearing Tefillin we engage in relationship in order to elevate our minds perceptions as well as our actions. These things become elevated by allowing them to be affected by the other in the relationship. We take pride in our actions and thoughts when they express the one we love, since we are so proud of that person. If our actions and thoughts express that person, how elevated we are.
The best example of this is in a beautiful marriage in which the man is so proud and thankful to married to his wife, that the more his individuality is an expression of her, the greater he feels of himself. (The individuality is not lost because she feels the inverse about him, so she pushes for him to express himself. If she is selfish, she will subsume him entirely, and vice versa if she is proud of him and he is selfish).
We have not explored the specific nature of the connection between our thoughts and actions, so we are still vague on why we need to elevate them separately of each other. But we have begun to understand why they are parallel to the sun and moon relationship. We will see more of this when we consider that the moon does reflect the sun's light. Actions reflect our thoughts, and there is a reverse feedback also in which the mind becomes informed by our actions - similar to the sun being able to shine down only on that which grew in the cycles controlled by the moon.
3) We need to get into much more detail here. The first thing is to consider that although the sun and moon are the male-female roles, they somehow both end up in the Mitzvah of Tefillin which is worn by men. So clearly the "feminine" aspect here is referring to something that applies to men. Let's explore this.
So far we have been vague and said that the hand Tefillin is symbolic of action. This is, however, oversimplified. Although the hand is about action, the hand Tefillin is elevating something far greater than this. Recall, the hand Tefillin is the moon which is feminine and yet is somehow completely applicable to a man wearing Tefillin.
What is the feminine aspect of masculinity? If masculinity's most emphsized characteristic is the manufacturing of vision and a desire to assert that vision, what is the diminished feminine element that should accompany this? When you think about it, you realize that it is the concept of feedback.
In order to create a vision that is viable and applicable, you need to be aware of the environment in which you will operate that vision. A pure man could care less about the environement and will convince himself that not only can he assert his vision for how things should be, but he can even control the field in which the vision is asserted. This is clearly stupid and many a men have paid dearly for this brutal error. Certainly a man could and often should assert his vision, however, he must stay completely responsive to the environment in which he acts. Otherwise, he inevitably acts brutally, cruelly and coercively.
Simply put, the feminine aspect so dear to healthy masculinity is the ability to gain feedback from one's surrounding and subsequesntly integrate that into the vision he wishes to set forth in the world. This is truly feminine since it involves feedback from environment. In a man, since the primary emphasis and focus of his activity are vision-based, we call the aforementioned idea feminine-masculinity. [The inverse in a woman is masculine-femininity and refers to the woman needing to act with vision in certain ways despite that being highly diminished to her general poise and reason d'etre. These concepts lie at the bedrock of the discussion as to whether a woman should or should not wear Tefillin].
This being the case, we would say that tefillin Shel Yad are about feedback and integration of feedback. This is very important to understanding why the Talmud seems to leave out references to Tefillin Shel Yad of G-d, and the Zohar while ultimately admitting to such a thing, seems hesitant to discuss it until R' Elazar pushes R' Shimon to disclose this custom. However, we will discuss this later. The main point is to realize that Tefilin Shel yad is feedback and integration of feedback. We will discuss this in detail soon.
4) To better understand this concept, we need to turn to the aspect of Tefillin which sees itself as a Keter or crown, connoting royalty. The axiomatic king for the Jewish people is King David, of course. There are two outstanding qualities that can be learned from David among many. The first is T'zniut, which we won't focus on here but will mention for reasons you will see shortly. The second, much more nessecary for us, is the trait of Anavah - humility.
In our mind we think of a king as protoypically male. After all, the king gives vision and asserts it more than any other human being - מלך פורץ גדר, "the king breaks down all fences to build his roads". Surprisingly, in Kabbalah, the Kingship is actually considered among the feminine attributes or Sephirot. How do we reconcile these distinct aspects, especially considering that Halacha does not allow a woman to be granted the actual right of Kingship?
To keep this conversation brief, let's suffice it that the King is not asserting "his" vision. In fact, the Jewish conception of good Kingship is a King who asserts (masculine) the vision of the people he leads (feminine). His job is to disappear as an individual and become entirely subsumed within the vision of the people. The idea being, that the people are not capable of asserting their vision because of the awkwardness and cumbersome nature of large bodies of people trying to act in coordination. (Sociologists cap group efficiency at no larger than 150 individuals!). The King of the holiest people must act completely selflessly and change his entire nature into one of feminine-masculinity. (Malchut, despite being female, is the only female Sephira that falls on the center axis of the Kabbalsitic matrix of Sephirot D' Yosher. Obviously this implies almost explicitly that we are dealing with masculinity acting strongly within its feminine elements. There is too much to write about this, unfortunately we cannot deal with this beautiful and powerful concept here).
How does a man achieve this? Humility. That is why King David became the paradigm of humility.
What does this have to do with Tefillin Shel Yad? Obviously it is conceptually one, as you should have noticed already. However, astonishingly, the Hebrew numeric value of the word David, spelled in Hebrew as: דוד, is the exact same as the numerical value for the Hebrew word for hand, spelled: יד. (David is 4+6+4, and Hand is 10+4).
Clearly, the humility that is required by a male in order to access his feminine-masculinity and be receptive to his environment and even be willing to integrate into his masculine-masculine vision that which he has learned from his environment, this all takes tremendous efforts in humility.
This should help clarify what we mean by feminine-masculinity, and begin to paint the picture of why the hand Tefillin is an embodiment of this concept.
Another important and fundamental aspect of the hand Tefillin is that it must be a box that is covered (T'zniut, the first trait of David we mentioned above) and that a strap descend and is tied to the middle finger. Why the middle finger? Because it is the finger that touches and reaches out, being the longest on the hand. The Tefillin Shel Yad encourages us to act with humility and modesty to reach out and touch and learn about our surroundings. This is all part of the same concept that we have described.