This means that the entire array of the Sefirot was to unfold... Here we call all the Sefirot one side – the Holy Side – and the whole of the Other Side a different side, for the reason we have mentioned. For the power of Judgment and the root of evil that we have mentioned in relation to the Sefirot are all called one extension from the primordial Root, in accordance with the Tzimtzum willed by Him. All that we can discern is that the power of strict Judgment contained in the Sefirot is the newly instituted root of evil, because of the power of the deficiencies revealed through the Tzimtzum.
The Holy Side and the Other Side of the Sefirot
Kalach Pitchei Chokhmah 30:51