Adapted from the Lubavitcher Rebbe’s teachings by Rabbi Y. Y. Jacobson 
The Sukkah hut is frail and vulnerable, but its walls have basic  specifications: They must be two full walls, plus a third wall of only  3.5 inches, measured in Hebrew as a ‘Tefach’ handbreadth. It’s okay to  have 3 or 4 full walls; but the minimum is two plus a tiny bit of a third.
What is the spiritual significance of this tiny third handbreadth-size wall?
Anatomy of an Embrace
Two great Jewish thinkers, Rabbi Isaac Luria and Rabbi Schnuer  Zalman of Liadi, turn our attention to the affectionate words uttered by  the Bride in the Song of Songs: "His left arm is under my head, and His  right arm embraces me."
These metaphors address two distinct moments in the relationship  between G-d, the Groom, and His people, the Bride. During the Rosh  Hashanah and Yom Kippur "days of awe," G-d's "left arm," as it were, is  under the head of Israel. The left side represents introspection, strict  discipline and awe.
Sukkos, on the other hand, is "the time of our joy," when “G-d's right arm embraces me." 
Our arm is divided into 3 sections. The first is the arm itself,  from the shoulder to the elbow; the second is the forearm, from the  elbow to the wrist; and the third is from the wrist to the fingertips.
Our Sukkah walls represent the "right arm's embrace." The first  full wall represents a Divine embrace from the "shoulder" to the  "elbow;" the second wall reflects the "forearm," and the third tiny wall  symbolizes the palm’s embrace.  
 Expressions of Love
There are three ways of expressing love. 
The first is words. "I love you," when uttered sincerely, has  impact. A second, more powerful expression of love is a kiss. A genuine  kiss expresses a deep intense feeling that may not be grasped in words.  Words can state, "I love you," while a kiss declares, "I love you more  then I will ever be able to tell you."
An embrace is a third expression of love.
Dissecting the Hug
Which form of love do children cherish most?
Children enjoy being spoken to. They certainly take pleasure from  being kissed. Yet, most children, especially infants, cherish being  hugged. When our children hurt themselves or break something, they cry  and come running to their parents for a hug to calm them down and to  restore their confidence.
Two significant features set apart an embrace from the other "love communicators."
Affection is directed primarily toward the face of the beloved. You  speak to one's face, kiss one's cheeks or lips, or gaze at one's eyes.  An embrace involves the nape and back of the one being embraced.
Another feature that distinguishes an embrace is the firm physical  bond of a hug. When I utter words of love, even when I kiss, I am not  holding on to you. But when I embrace you, even if you wish to escape my  embrace, you are "trapped" in my gripping hug; I don't let you tear  yourself away from me.
Two forms of love
There is reciprocal love and unconditional love. The first is  directed to the face of the beloved one; the second is directed to the  back of the beloved.
I may love you because of what I receive in return for my  relationship. You may be wise, deep, sensitive, kind, beautiful,  humorous, challenging etc. - qualities expressed through your face,  eyes, ears and mouth - and I love you because of these or other  qualities that enrich my life.
This type of love is communicated in words of affection, or in a  kiss, directed toward the face of the beloved, the primary location of  reciprocity. Expressing my attachment in these forms shows that I  cherish you because of your qualities. 
This love may be deep and can bestow blessings and fulfillment.  Yet it is conditional on reciprocity. As long as you are here for me, I  am here for you. In essence, I love you because I love myself, and you  make my "self" so much deeper and happier.
Yet there is a deeper love of an embrace, in which my arms encircle  your backside. The hug represents an unconditional, unqualified and  absolute love. It is not about your face, it is about your back, an area  lacking meaningful reciprocity. I don't love you because of me; I love  you because of you. You may not give me anything in return for my love,  you may even want me out of your life, but I still love you with all my  heart. 
Do you embrace your children?
That’s why children need their parents to embrace them.
When children get hurt or break something, they are searching for  affirmation that their validity was not compromised. They are yearning  to hear that their value does not depend on them being perfect and  impeccable, but that their dignity is absolute. "Show me," asks the  child, "that you love me unconditionally because of who I am and not  because of what I achieve."
When a child cries because their finger is bleeding, and you  simply place a band aid on the wound and go away, you may have forfeited  the opportunity to teach your child the most important lesson: Your  dignity stems from your very being. Even when you will fall in life and  bleed badly, your very being and identity is indispensable.
We also relate to G-d on these two levels.
All year around, G-d's light relates to us as a result of the  choices we make. The more we rise to the higher truth, the more we hear  G-d’s silent voice resonating in our souls.
Throughout the year, we experience G-d's presence only through our  efforts and toil to refine our behavior. When we meditate, pray,  reflect, study and live morally and holy, we catch a glimpse of G-d's  love toward us. When I work against my immoral temptations and cravings,  I can at times sense a reciprocal kiss from G-d.
Throughout the year, we enjoy a reciprocal relationship with G-d.  G-d might talk to you, He may even kiss you or gaze at you, but You must  show Him your face. If you don't turn your back on Him, He will be  there for you.
But during Sukkot, G-d shares His love unconditionally and embraces us.
We eat, drink, chat, and relax in a Sukkah- all mundane activities  with little spirituality. Yet when  performed in the Sukkah, these acts  are a Mitzvah, a medium through which we relate to Him.
The Sukkah walls are saying: I love and cherish you not because of  what you do for me or because of what I gain from you. I am attached to  you not because of your spiritual sophistication or because of your  noble pursuits. I love you because I love you. I am one with you as you  are. I am in love with your very core. 
So for a real good hug, spend time in a Sukkah.
Sustaining the Embrace
 Each Jewish holiday leaves us with a special energy that  affects the entire year. This Divine “hug” even while we are in a  physical mode, empowers and inspires us to transform our physical and  mundane endeavors throughout the year into tools through which to bring Divine light into the world.