If so, we may say that the roots of graded, measured government lie in this Place. But that the Place of the created realms and beings should be one of gradation and measure, as opposed to one that follows some other pathway, is rooted in the Tzimtzum itself. On the basis of what we have explained here, you can understand that, had it not been for the Tzimtzum, even though this Place was included in Eyn Sof in potential, it would not have emerged in actuality. If so, the Tzimtzum was the cause of the Place, yet it could have come into being in some other manner.
Tzimtzum as the Core Mystery of the Patriarchs
Kalach Pitchei Chokhmah 30:13