"'You could bind the ka of a man to his body"

GNU Free Documentation LicenseMeskhenet - Credit: Jeff Dahl
Ancient Egyptians saw the human soul as having five parts, the Ren (name), the Ba (soul), the Ka (spirit), the Sheut (shadow) and the Ib (heart).

The Ka is the thing that marks the difference between the living and the dead, when you die the ka leaves the body.

Heket or Meskhenet is the creator of everyones ka, breathing it into them as they are born. Ka is sustained through food and drink and this is why they were often presented to the dead.