7 is the number of all possibilities and the divine force behind the physical world. The connection of the six attributes at the center of a cube fundamentally reveals the nature of 7.
There are 7 notes on the musical scale, 7 directions (left, right, up, down, forward, back and center) and 7 colors in a rainbow. When we look at a cube we find that the physical has six opposing sides, which are: top, bottom, right, left, front and back. These six sides are related to the physical, because each side has extent, and limits physical objects. But, it also has a seventh, the center, which has no exposure on any side. It is the non-physical, which has no extension and takes up no volume of space. It’s the content behind all matter.