[A]ngels made no complaint about any of the creatures that were created during the six days of Creation, except about Man. This is because he was created in God's image and consists of Upper and Lower together. When the angels saw it, they were startled and bewildered. How would the pure, spiritual soul descend from its sublime degree, and come and dwell in the same abode with this filthy, beastly body? (...) The answer that came to them is is that there is already a tower filled abundantly, and empty of guests. To fill it with guests, we need the existence of this human, made of Upper and lower together (...) Know that this tower, filled abundantly, implies all the pleasure and the goodness for which He has created the creatures.
Yehuda Ashlag