. For the deep is nothing else than a huge quantity of water whose limit man cannot comprehend. In the beginning, indeed, the water lay all over the surface of the earth. And first God created the firmament to divide the water above the firmament from the water below the firmament. For in the midst of the sea of waters the firmament was established at the Master's decree. And out of it God bade the firmament arise, and it arose. Now for what reason was it that God placed water above the firmament? It was because of the intense burning heat of the sun and ether  . For immediately under the firmament is spread out the ether  , and the sun and moon and stars are in the firmament, and so if water had not been put above it the firmament would have been consumed by the heat  .
Next, God bade the waters be gathered together into one mass  . But when the Scripture speaks of one mass it evidently does not mean that they were gathered together into one place: for immediately it goes on to say, And the gatherings of the waters He called seas  : but the words signify that the waters were separated off in a body from the earth into distinct groups. Thus the waters were gathered together into their special collections and the dry land was brought to view. And hence arose the two seas that surround Egypt, for it lies between two seas. These collections contain  various seas and mountains, and islands, and promontories, and harbours, and surround various bays and beaches, and coastlands. For the word beach is used when the nature of the tract is sandy, while coastland signifies that it is rocky and deep close into shore, getting deep all on a sudden. In like manner arose also the sea that lies where the sun rises, the name of which is the Indian Sea: also the northern sea called the Caspian. The lakes also were formed in the same manner.
The ocean, then, is like a river encircling the whole earth, and I think it is concerning it that the divine Scripture says, A river went out of Paradise  . The water of the ocean is sweet and potable  . It is it that furnishes the seas with water which, because it stays a long time in the seas and stands unmoved, becomes bitter: for the sun and the waterspouts draw up always the finer parts. Thus it is that clouds are formed and showers take place, because the filtration makes the water sweet.
This is parted into four first divisions, that is to say, into four rivers. The name of the first is Pheison, which is the Indian Ganges; the name of the second is Geon, which is the Nile flowing from Ethiopia down to Egypt: the name of the third is Tigris, and the name of the fourth is Euphrates. There are also very many other mighty rivers of which some empty themselves into the sea and others are used up in the earth. Thus the whole earth is bored through and mined, and has, so to speak, certain veins through which it sends up in springs the water it has received from the sea. The water of the spring thus depends for its character on the quality of the earth. For the sea water is filtered and strained through the earth and thus becomes sweet. But if the place from which the spring arises is bitter or briny, so also is the water that is sent up  . Moreover, it often happens that water which has been closely pent up bursts through with violence, and thus it becomes warm. And this is why they send forth waters that are naturally warm.
By the divine decree hollow places are made in the earth, and so into these the waters are gathered. And this is how mountains are formed. God, then, bade the first water produce living breath, since it was to be by water and the Holy Spirit that moved upon the waters in the beginning  , that man was to be renewed. For this is what the divine Basilius said: Therefore it produced living creatures, small and big; whales and dragons, fish that swim in the waters, and feathered fowl. The birds form a link between water and earth and air: for they have their origin in the water, they live on the earth and they fly in the air. Water, then, is the most beautiful element and rich in usefulness, and purifies from all filth, and not only from the filth of the body but from that of the soul, if it should have received the grace of the Spirit  .
Concerning the seas  .
The Ægean Sea is received by the Hellespont, which ends at Abydos and Sestus: next, the Propontis, which ends at Chalcedon and Byzantium: here are the straits where the Pontus arises. Next, the lake of Mæotis. Again, from the beginning of Europe and Libya it is the Iberian Sea, which extends from the pillars of Hercules to the Pyrenees mountain. Then the Ligurian Sea as far as the borders of Etruria. Next, the Sardinian Sea, which is above Sardinia and inclines downwards to Libya. Then the Etrurian Sea, which begins at the extreme limits of Liguria and ends at Sicily. Then the Libyan Sea. Then the Cretan, and Sicilian, and Ionian, and Adriatic Seas, the last of which is poured out of the Sicilian Sea, which is called the Corinthian Gulf, or the Alcyonian Sea. The Saronic Sea is surrounded by the Sunian and Scyllæan Seas. Next is the Myrtoan Sea and the Icarian Sea, in which are also the Cyclades. Then the Carpathian, and Pamphylian, and Egyptian Seas: and, thereafter, above the Icarian Sea, the Ægean Sea pours itself out. There is also the coast of Europe from the mouth of the Tanais River to the Pillars of Hercules, 609,709 stadia: and that of Libya from the Tigris, as far as the mouth of the Canobus, 209,252 stadia: and lastly, that of Asia from the Canobus to the Tanais, which, including the Gulf, is 4,111 stadia. And so the full extent of the seaboard of the world that we inhabit with the gulfs is 1,309,072 stadia  .
 Genesis 1:2.  See Basil, Hexaëm., Hom. 3.  Text, hupheplotai. Variant, epheplotai.  Basil, Hom. 2 in Hexaëm.; Sever. Gabal., Orat. de opific. mundi.  Genesis 1:9.  Genesis 1:10.  Text, sunechthesan. R. 2927 has diestesan: Edit. Veron. Reg. 3362 has hothen sunestesan: Colb. 1 has othen suneste.  Genesis 2:10.  For potamos de ho gluku hudor echon esti, reading potimon kai gluku hudor echon.  Basil, Hom. 4 in Hexaëm.  Genesis 1:2.  Sever. Gabal., Orat. 4, De opific. mundi: Basil, Hom. 8.  This chapter is wanting in certain copies, Reg. 7, Colb. 1, R. 2930. In Cod. Hil. it is given after the chapter On Creation.  Vide Strab. bk. ii.
 See Basil, Hexaëm., Hom. 3.
 Text, hupheplotai. Variant, epheplotai.
 Basil, Hom. 2 in Hexaëm.; Sever. Gabal., Orat. de opific. mundi.
 Genesis 1:9.
 Genesis 1:10.
 Text, sunechthesan. R. 2927 has diestesan: Edit. Veron. Reg. 3362 has hothen sunestesan: Colb. 1 has othen suneste.
 Genesis 2:10.
 For potamos de ho gluku hudor echon esti, reading potimon kai gluku hudor echon.
 Basil, Hom. 4 in Hexaëm.
 Genesis 1:2.
 Sever. Gabal., Orat. 4, De opific. mundi: Basil, Hom. 8.
 This chapter is wanting in certain copies, Reg. 7, Colb. 1, R. 2930. In Cod. Hil. it is given after the chapter On Creation.
 Vide Strab. bk. ii.