But here the question is how it could be that the whole earth was watered by one fountain, not only on account of its size, but also because of the inequality of the mountainous and champaign situations? Unless, indeed, just as the whole force of the king's cavalry is called "the horse," so the whole multitude of the veins of the earth which supply drinkable water, may perhaps be called the fountain, inasmuch as they all bubble up like a fountain.
And that expression is peculiarly appropriate which says that the fountain watered, not the whole earth, but its face; as in the living being it waters the chief and predominant part (the mind or the countenance). Since that is the most important part of the earth which can be good and fertile and productive, and that is the part which stands in need of the nourishment of fountains.