Why God commanded the waters to gather

'Let the waters be gathered, and let the dry land appear' (Genesis 1:9). The curtains are drawn together, so that what was previously unseen may become visible. Perhaps someone might seek in addition this further point. First, why does the account attribute to the command of the Creator what belongs to water by nature—its movement toward a downward slope? For as long as water happens to lie on level ground, it is still, having nowhere to flow. But when it takes hold of some downward incline, when the leading water rushes forward, the water continuous with it seizes the base of the one that moved, and the following water seizes the base of that one. And so the leading water always escapes from under, while the water coming after pushes it on. And the flow becomes swifter the greater the weight of what is carried down and the deeper the hollow into which the influx runs. If water is like this by nature, then the command ordering it to be gathered into one gathering would be superfluous. For it was bound to run together of its own accord, because of the downward tendency of its nature, into the deepest region of all, and not to stop until its surface was leveled. For no place is as level as the surface of water. Then, someone says, how was the water commanded to run together into one gathering, when there are clearly many seas, separated from one another by great distances in their position? To the first of these questions we say this: you have come to know the movements of water after the Master's command—that it flows downward and is unstable, and is carried by nature toward slopes and hollows. But before that, what power it had before the course from this command was born in it, you neither saw yourself nor heard from anyone who saw. Understand that the voice of God is maker of nature, and the command given then to creation provided the continuity for what was created thereafter. Day and night were made once, and from that time until now they succeed one another and divide time in equal portions without ceasing. 'Let the waters be gathered.' The nature of the waters was commanded to run, and it never grows weary, urged on continually by that command. I say this with reference to the flowing portion of the waters. For some flow of their own accord, such as springs and rivers; others are artificially collected and without outlet. But my subject now is the rushing waters. 'Let the waters be gathered into one gathering.' If you have ever stood by a spring that sends up abundant water and wondered: Who is it that pushes this water from the flanks of the earth? Who urges it forward? What are the storehouses from which it comes? What is the place to which it hurries? How is it that these do not fail, and those are not filled up? All this depends on that first voice. From there the water received the signal to run. In every account of waters, remember the first voice: 'Let the waters be gathered.' They had to run, so that each might reach its proper place; then, having come into the appointed regions, to remain by themselves and go no further. For this reason, according to the word of Ecclesiastes, 'All the torrents go to the sea, and the sea is not filled' (Ecclesiastes 1:7).