Six is a number perfect in itself, and not because God created the world in six days; rather the contrary is true. God created the world in six days because this number is perfect, and it would remain perfect, even if the work of the six days did not exist.
In the early days of the world, the Almighty said to the first of our race "In the sweat of thy face shalt thou eat bread"; and since then, if we except the light and the air of heaven, no good thing has been, or can be enjoyed by us, without having first cost labour.