The 12th of Tishrei is the yahrtzeit (anniversary of the passing) of Rabbi Abraham (1740-1776) the son of Rabbi DovBer of Mezeritch and study partner of Rabbi Schneur Zalman of Liadi; known as "Rabbi Abraham the Angel" for his saintliness and ascetism.
On Yom Kippur, the souls return to connect to their origin, carrying with them the divine sparks from all they've done in this world.
Their return rises like an aroma of burning incense through the atmosphere, and through endless strata of spiritual realms, until it reaches a place beyond higher and lower. It reaches the essence of G-d.
And there it becomes the essence of pure and ultimate bliss.
On Sukkot, that divine, supernal delight reappears in our world, much as a cloud condenses from the vapor rising from the sea.
And it manifests as the branches and leaves covering our Sukkah.
So that within the Sukkah, we are embraced by G-d’s delight in us, and we rejoice.