Tohus Vs. Tikkun
Rabbi Y. Oliver
Above these worlds lies the world of Tohu, lit. “chaos,” which is alluded to in the verse, “And the earth was chaos.” This realm lies in a state of destruction and devastation. The Arizal teaches that when the Medrash says that Hashem “built worlds and destroyed them,” this refers not to physical worlds, but to exceedingly lofty spiritual realms that lie in a state of destruction—the worlds of Tohu.
This is the deeper meaning of our Sages’ interpretation of the verse, “Back and front you have formed me” to mean that mankind is “back,” i.e., last of all of Hashem’s creations, for Adam, who represents medaber, mankind, was the last being to be created on the sixth and last day of creation. Kabbalah interprets this to mean that the source of all the other creations is “front,” i.e., higher—the level of Tohu, while the source of medaber is “back,” i.e., lower—the level of Tikkun.
 Bereshis 1:2.
 Bereshis Rabbah 3:7; Koheles Rabbah 13:11.
 Tehillim 139:5.