For there are necessarily two entities (מציאויות, metziuyot) – i.e. the Likeness of Man must be understood in two ways: (1) as the order of government (הנהגה, hanhagah) consisting of all these different kinds of governmental laws; (2) as the design of the image or representation (מראה, mar’eh) of that governmental order as seen in the separate creations themselves down below (for it is they who are governed).
One general law is necessary to give existence to both. To produce the separate creations in themselves, there has to be one power that governs the form in which they are designed, and this power stands over the separate creations themselves to maintain them in their appointed form. This is what Sefer Yetzirah calls Tzur Tak, (צור טק, TzuR TaK, “the ‘knot of forms’ – for all the forms designed in the world were designed out of this” – Raavad, Introduction to Sefer Yetzirah).
This contains the power to bring forth the separate creations into actual being out of nothingness (יש מאין, yesh meayin) so as to be branches of it. This is because it is a unique kind of radiation that produces no other branches except separate creations, being out of nothingness, in accordance with the unique aspect of this power.