באתי לגני אחותי כלה
I have come to my garden: my sister, bride. Shir HaShirim (5:1)
The midrash explains that my garden is an intimate place. It is private and beautiful. Further, my garden (גני) is translated into Aramaic as my chupah (גנוני), under which the bride and groom are bound together.
Taken from the prophetic perspective, this is revealing the depth of the connection between HaVaYa, the supernal utterly simple being, and this world, the lowest purposeful realm.
The initial state of creation is to be completely conscious of the Shechinah, the transcendent dwelling within. Then the event called eating the tree of knowledge of good and bad transitioned man into becoming self-conscious. This causes the oneness consciousness to be hidden under a layer.
For seven generations this oneness became even more concealed, through violence, theft, perversions, etc.. A turning point happened with the revolutionary called Avraham. By him challenging the principles of society and passing ten tests, he uncovered one layer. Seven generations from Avraham to Moshe our teacher drew down the Shechinah from the seventh Heaven to the physical world.
This is why the Eternal One told Moshe to build the Mishkan, a sanctified space to experience the marriage of heaven and earth. As it says in the Torah: Make for me a mikdash and I will dwell within them. This is the revelation of the Shechinah within every individual.
From the instructions of the Mishkan, the Frierdiker Rebbe teaches us fundamental lessons in fulfilling our purpose and mission. The Mishkan is built using shittim (שטים) wood. The hebrew word shittim is related to shtus (שטות), foolishness. On this the Gemara teaches that the only way someone will go against the will of the creator is by being overcome by a ruach shtus, a foolish spirit. This is the irrational impulsive drive that gets us into trouble.
In order to transform this aspect of us, we must counter it with shtus d'kedusha, holy foolishness. This is a commitment to connecting with the Eternal One that is beyond logic. In this spirit, the Rebbe instituted multiple campaigns such as teaching the laws given to Noah, putting on tefillin, lighting shabbos candles. We do this simply because it is the will of the creator. Sure there are plenty of reasons and benefits. But the connection is much beyond anything that can be put into words by the mind.
This transformation is the purpose of building our personal mishkan and the means to higher consciousness. Through this personal revelation the essence that cannot be described becomes revealed even in this physical world, transforming tangled concealments into my garden.
A second lesson can be learned from how the beams are called krashim (קרשים). This word has the same letters as sheker (שקר), a lie, and kesher (קשר), a knot. It is upon us to transform the lies of this world, the concealments and distractions into beams to build the Mishkan. Ultimately this is about connecting everything in this world and the ultimate essence of being which all are expressions of and united with.
This summary is based on the translation found here: http://downloads.simplychassidus.com/Basi_LeGani_5719_section_one.pdf
More about HaVaYa/HaShem: https://www.chabad.org/library/article_cdo/aid/2123175/jewish/Infinite-Light.htm
More about Shechinah: https://www.chabad.org/library/article_cdo/aid/2438527/jewish/The-Shechina.htm