5 And God said: “Let the waters be gathered together unto one place and let the dry land appear.” He did not say let the earth appear, so as not to show itself again without form, mud-like, and in combination with the water, nor yet endued with proper form and virtue. At the same time, lest we should attribute the drying of the earth to the sun, the Creator shows it to us dried before the creation of the sun. Let us follow the thought Scripture gives us. Not only the water which was covering the earth flowed off from it, but all that which had filtered into its depths withdrew in obedience to the irresistible order of the sovereign Master. And it was so. This is quite enough to show that the Creator's voice had effect: however, in several editions, there is added “And the water which was under the heavens gathered itself unto one place and the dry land was seen;” words that other interpreters have not given, and which do not appear conformable to Hebrew usage. In fact, after the assertion, “and it was so,” it is superfluous to repeat exactly the same thing. In accurate copies these words are marked with an obelus, which is the sign of rejection.
“And God called the dry land earth; and the gathering together of the waters called He seas.” Why does Scripture say above that the waters were gathered together unto one place, and that the dry earth appeared? Why does it add here the dry land appeared, and God gave it the name of earth? It is that dryness is the property which appears to characterize the nature of the subject, while the word earth is only its simple name. Just as reason is the distinctive faculty of man, and the word man serves to designate the being gifted with this faculty, so dryness is the special and peculiar quality of the earth. The element essentially dry receives therefore the name of earth, as the animal who has a neigh for a characteristic cry is called a horse. The other elements, like the earth, have received some peculiar property which distinguishes them from the rest, and makes them known for what they are. Thus water has cold for its distinguishing property; air, moisture; fire, heat. But this theory really applies only to the primitive elements of the world. The elements which contribute to the formation of bodies, and come under our senses, show us these qualities in combination, and in the whole of nature our eyes and senses can find nothing which is completely singular, simple and pure. Earth is at the same time dry and cold; water, cold and moist; air, moist and warm; fire, warm and dry. It is by the combination of their qualities that the different elements can mingle. Thanks to a common quality each of them mixes with a neighbouring element, and this natural alliance attaches it to the contrary element. For example, earth, which is at the same time dry and cold, finds in cold a relationship which unites it to water, and by the means of water unites itself to air. Water placed between the two, appears to give each a hand, and, on account of its double quality, allies itself to earth by cold and to air by moisture. Air, in its turn, takes the middle place and plays the part of a mediator between the inimical natures of water and fire, united to the first by moisture, and to the second by heat. Finally fire, of a nature at the same time warm and dry, is linked to air by warmth, and by its dryness reunites itself to the earth. And from this accord and from this mutual mixture of elements, results a circle and an harmonious choir whence each of the elements deserves its name. I have said this in order to explain why God has given to the dry land the name of earth, without however calling the earth dry. It is because dryness is not one of those qualities which the earth acquired afterwards, but one of those which constituted its essence from the beginning. Now that which causes a body to exist, is naturally antecedent to its posterior qualities and has a pre-eminence over them. It is then with reason that God chose the most ancient characteristic of the earth whereby to designate it.
6. “And God saw that it was good.” Scripture does not merely wish to say that a pleasing aspect of the sea presented itself to God. It is not with eyes that the Creator views the beauty of His works. He contemplates them in His ineffable wisdom. A fair sight is the sea all bright in a settled calm; fair too, when, ruffled by a light breeze of wind, its surface shows tints of purple and azure,— when, instead of lashing with violence the neighbouring shores, it seems to kiss them with peaceful caresses. However, it is not in this that Scripture makes God find the goodness and charm of the sea. Here it is the purpose of the work which makes the goodness.
In the first place sea water is the source of all the moisture of the earth. It filters through imperceptible conduits, as is proved by the subterranean openings and caves whither its waves penetrate; it is received in oblique and sinuous canals; then, driven out by the wind, it rises to the surface of the earth, and breaks it, having become drinkable and free from its bitterness by this long percolation. Often, moved by the same cause, it springs even from mines that it has crossed, deriving warmth from them, and rises boiling, and bursts forth of a burning heat, as may be seen in islands and on the sea coast; even inland in certain places, in the neighbourhood of rivers, to compare little things with great, almost the same phenomena occur. To what do these words tend? To prove that the earth is all undermined with invisible conduits, where the water travels everywhere underground from the sources of the sea.
Source: Nine Homilies of Hexaemeron (New Advent)