...while the first three Sefirot are only crowns over the lower seven... Everything that stands outside a thing’s essential being – in the sense that the thing’s essential being is complete without it – can only be an extra crown adorning it but not an integral part of it. So it is in the case of the first three Sefirot, which are not the actual root of what goes on in this world but rather, they are crowns over that root.
This is properly so, because everything that happens in the world must certainly have a root of its own just to keep it in existence. It is not the basic existence of things in this world but rather their status that has to change depending on men’s deeds. Accordingly, two roots are needed here: a root for the unchanging existence of things and a root for their changing status.