Psalms 74:4

6. But now what? “The earth hath flowed down” ( ver. 3 ). If the earth hath flowed down, whence hath it flowed down except by sins? Therefore also they are called delinquencies. To delinquish is as it were by a kind of liquidity to slip down from the stability of firmness in virtue and righteousness. For it is through desire of lower things that every man sinneth: as he is strengthened by the love of higher things, so he falleth down and as it were melteth away by desire of lower things. This flux of things by the sins of man the merciful forgiver observing, being a merciful forgiver of sins, not yet an exactor of punishments, He observeth and saith: The earth herself indeed hath flowed down by them that dwell in her. That which followeth is an exposition, not an addition. …

9. Do you suppose that a heavier body prevents the earth from falling into the abyss? Then you must consider that this support needs itself a support to prevent it from falling. Can we imagine one? Our reason again demands yet another support, and thus we shall fall into the infinite, always imagining a base for the base which we have already found. And the further we advance in this reasoning the greater force we are obliged to give to this base, so that it may be able to support all the mass weighing upon it. Put then a limit to your thought, so that your curiosity in investigating the incomprehensible may not incur the reproaches of Job, and you be not asked by him, “Whereupon are the foundations thereof fastened?” If ever you hear in the Psalms, “I bear up the pillars of it;” see in these pillars the power which sustains it. …

Now we must say something about the nature of the firmament, and why it received the order to hold the middle place between the waters. Scripture constantly makes use of the word firmament to express extraordinary strength. “The Lord my firmament and refuge.” “I have strengthened the pillars of it.” “Praise him in the firmament of his power.” The heathen writers thus call a strong body one which is compact and full, to distinguish it from the mathematical body. A mathematical body is a body which exists only in the three dimensions, breadth, depth, and height. A firm body, on the contrary, adds resistance to the dimensions. It is the custom of Scripture to call firmament all that is strong and unyielding. It even uses the word to denote the condensation of the air: He, it says, who strengthens the thunder. …

The earth is one of the four elements, dry, cold, heavy, motionless, brought into being by God, out of nothing on the first day. For in the beginning , he said, God created the heaven and the earth : but the seat and foundation of the earth no man has been able to declare. Some, indeed, hold that its seat is the waters: thus the divine David says, To Him Who established the earth on the waters . Others place it in the air. Again some other says, He Who hangeth the earth on nothing . And, again, David, the singer of God, says, as though the representative of God, I bear up the pillars of it , meaning by “pillars” the force that sustains it. Further, the expression, He hath founded it upon the seas , shews clearly that the earth is on all hands surrounded with water. …