In this aspect, we do not take into account the individual levels of the Sefirot. Rather, each Sefirah with all its levels is considered as only one, so that altogether they make exactly ten. The general pathway of all their arrangements or institutions (תיקונים, tikkunim, lit. “repairs”) depends on this number through the mystery of the return of evil to good. All man’s service depends on this matter of the Ten Sefirot, and therefore everything involved in the Sefirot is only on the basis of ten, with all that depends on this. Thus the Ten Sefirot are ten individual kinds of government, each different from the others, but the general law that brings them all together to serve one purpose is that of the overall Ten Sefirot that constitute Adam Kadmon.
Each Sefirah Viewed as a Complete Unity in Itself
Kalach Pitchei Chokhmah 31:21