We saw earlier that the outer Tree of Life has 48 vertices, lines & triangles and that its inner, polygonal form has 48 corners. With its triangles turned into tetractyses, the lowest Tree of Life has 48 yods up to Chesed, the first Sephirah of Construction, the part of the Tree of Life marking the commencement of objective manifestation of the Divine Life. Surrounding the centre of the 2nd-order tetractys are 48 red yods symbolizing 7-fold differentiations of the seven Sephiroth of Construction, which are denoted by the seven tetractyses arranged at the centre and corners of a hexagon. The number 48 always characterizes holistic systems possessing sacred geometry (such as the Tree of Life) as the minimum number of degrees of freedom needed to express their form.