Note the plausible --- and often pointed out source --- is the Pythagorean Tetractys with its ten divine elements.
The harmonic evolution
digraph is
Tree = T4
Loops = L1 + 9 L7
Comment: The cabalist should be truly delighted by this feature. Although the structure of the Sephirot Tree seems to neglect the mystic number seven, yet the harmonic game reveals its hidden presence! Even more --- the tree part is a pure binary tree with 4 levels that may viewed as the Pythagorean tetractys with its 4 levels!