Concerning the Ten Commandments, which are the Heads of the Law (101-105)

Let us not pass by such a model of the most excellent ways of life, the practical and the contemplative; but let us always keep our eyes fixed upon it, and stamp a visible image and representation of it on our own minds, making our mortal nature resemble, as far as possible, his immortal one, in respect of saying and doing what is proper. And in what sense it is said that the world was made by God in six days, who never wants time at all to make anything, has been already explained in other passages where we have treated of allegories.

Now, those who have applied themselves to mathematical studies, fully explain the precedence and pre-eminence to which the number seven is entitled among all existing things, tracing it out with great care and exceeding minuteness and accuracy; for among numbers seven is the virgin number, the nature which has no mother, that which is most nearly related to the unit, the foundation of all

Now, indivisible nature has assigned to it the first, and highest, and immovable circumference, which the unit inspects and overlooks; but the divisible nature has received that circumference which is inferior both in power and in arrangement, which the number seven inspects, which, being divided into six parts, has produced what are called the seven planets;

not indeed that any of the heavenly bodies do really wander (πεππλάνηται), inasmuch as they all enjoy a divine, and happy, and blessed nature, to all of which characteristics a freedom from wandering is most closely akin: at all events, they always preserve a kind of identity in a constantly similar motion, and pass a long eternity without ever admitting any change or variation whatever. But because they revolve in a manner contrary to the indivisible and outermost sphere, they have been named planets (πλάνητες), though without any strict propriety, by men speaking at random, who have by such language attributed their own propensity to wander to the heavenly bodies, which, in fact, never quit that position in the divine lamp in which they have been originally placed.

For all these reasons, and more besides, the number seven is honoured. But there is no one cause on account of which it has received its precedence so completely, as because it is by its means that the Creator and Father of the universe is most especially made manifest; for the mind beholds God in this as in a mirror, acting, and creating the world, and managing the whole universe.