Everything that has to be joined in as a component in the resultant light so as to be fixed as a part of the governmental order is already joined from the outset, prior to its emergence from the place where it develops (concealed within the parent power) to the outside (as a Partzuf in its own right). For once it comes forth, its unique mode of government is known as soon as it emerges, and it descends under the upper branch (the parent power that produced it), and its mode of government is not susceptible to any change or increase in terms of its constituent parts. However the actual mode of government itself can “ascend” or “descend” depending on the higher lights that enter the Partzuf itself and give it new strength.
Why Imperfection Exists in God's Creation
Kalach Pitchei Chokhmah 66:15