Ambrose of Milan : "The river," we are told, "is separated into four branches." The name of one is Pishon, which encircles all the land of Hevila, where there is gold. And the gold of that land is good; bdellium and onyx are there. The name of the second river is Gihon. This river encircles all the land of Ethiopia. The name of the third river is Tigris, which river flows by the Assyrians. And the fourth river is the Euphrates. There are, therefore, four rivers. Pishon—so called by the Hebrews but named Ganges by the Greeks—flows in the direction of India. Gihon is the river Nile, which flows around the land of Egypt or Ethiopia. The land enclosed by the Tigris and Euphrates rivers is called Mesopotamia because it lives between these two rivers. This name conveys its location even to far-distant peoples and besides expresses popular belief. But how is the fount called the Wisdom of God? That this is a fount the Gospel tells us in the words "If anyone thirst, let him come to me and drink." Wisdom is a fount according to the prophet: "Come and eat my bread and drink the wine which I have mingled for you." As Wisdom is the fountain of life, it is also the fountain of spiritual grace. It is also the fountain of other virtues that guide us to the course of eternal life. Therefore, the stream that irrigates paradise rises from the soul when well tilled, not from the soul that lies uncultivated. The results from it are fruit trees of diverse virtues. There are four principal trees that constitute the divisions of Wisdom. These are the well-known four principal virtues: prudence, temperance, fortitude and justice. The wise men of this world have adopted this division from us and transferred it to their writings. Hence, Wisdom acts as the source from which these four rivers take their rise, producing streams that are composed of these virtues.Pishon, therefore, stands for prudence. Hence it has pure gold, brilliant rubies and topaz stones. We often refer to wise discoveries as gold, as the Lord says, speaking through the prophet: "I gave to them gold and silver." Daniel says of the wise: "If you sleep among the midst of the lots, you shall be as the wings of the dove covered with silver and the hinder parts of her back like to gold." In this way one who puts his trust in the aid of the Old and New Testament can by resourceful inquiry attain the inmost secrets of the Wisdom of God. Here, therefore, is found pure gold, not the metal that is melted, which belongs to this earth and is subject to corruption. In this land, we are told, there is found the brilliant ruby stone in which there exists the vital spark of our souls. Here, too, is the topaz stone that by the nature of its color reveals an effect of greenness and vitality. Plants that are alive give forth green sprouts, while those that are dead are sapless and dry. The earth grows green when it is in bloom. The seeds, too, sprout forth green shoots in their periods of growth. The river Pishon is rightfully given first place. The Hebrews call it Pheoyson, which means "change of mouth," because it flows even through Lydia and not merely around one nation, for Wisdom, which is of benefit to all men, is productive and useful. Hence, if a person were to leave paradise, this river of Wisdom would be the first object he would meet. Thus he may not become inert and arid and his return to paradise may be facilitated. Many men resort to this river, which is considered to have marvelous beauty and fecundity. Accordingly it is regarded as a figure of Wisdom, which confers manifold fruits in the coming of the Lord of salvation. It flows to the very ends of the earth, because by Wisdom all have been redeemed. Thus it is written: "Their sound has gone forth into all the earth and their words unto the end of the world." — On Paradise Bede : Which then is divided into four heads: the name of the first is Pishon. It is established, according to the most certain authorities, that the sources of all these rivers, which are said to go out from paradise, are known in our land. The source of the Pishon, which is now called the Ganges, is indeed in the places of the Caucasus mountains; but the Nile, which the Scripture, as we have said, names Gihon, now far from Mount Atlas, which is the furthest end of Africa to the west. Furthermore, the Tigris and Euphrates from Armenia, from where it is believed that the place of paradise itself is most distant from human knowledge, and from there the four parts of the waters are divided; but those rivers, whose sources are said to be known, are somewhere beneath the earth and after passing through extended regions erupt in other places, where they are reputed to be known in their sources. For who is unaware that some waters are accustomed to do this? But it is known there where they do not run under the earth for long. Finally, historians report that the same rivers Tigris, Euphrates, and Nile are taken up in many places of the earth, and after some interval reemerging, continue their usual course; which is also believed to be done by the Lord as a sign of that course by which they come to us from paradise through the more hidden channels and longer veins of the earth. Now Phison is interpreted as change of mouth, and rightly, because indeed it shows another appearance for our benefit, that is, much more humble than it has in paradise. — Commentary on Genesis (Hexaemeron) Bede : This is the one which encircles the whole land of Havilah. This is the region of India, deriving its name from being settled after the flood by Havilah, son of Joktan, who was the son of Eber the patriarch of the Hebrews, whom Josephus also reports with his brothers possessed the land from the river Cephen and the region of India to the place called Hieria. — Commentary on Genesis (Hexaemeron) Cosmas Indicopleustes : The river Phison separates all the countries of India [lying along its course] from the country of the Huns. In scripture the Indian region is called Euilat (Havilah). For it is thus written in Genesis: Now the river goeth out from Eden to water Paradise. And from there it was parted and became four heads. The name of the first is Phison (Pishon); that is it which compasseth the whole land of Euilat, where there is gold; and the gold of that land is good; there is the carbuncle and the jasper stone; where the writer clearly calls the country Euilat. This Euilat, moreover, is of the race of Ham. For thus again it is written: The sons of Ham, Cush and Misraim, Phut and Caraan the sons of Cush, Sabâ and Euilat; that is the Homerites and Indians, for Sabâ is situated in the Homerite country, and Euilat is in India. For the Persian Gulf divides those two countries. And that country has gold according to sacred scripture. It has also the pezerôs which Scripture calls anthrax (carbuncle) and the jasper stone, by which it designates the leek-green stone. Clearly therefore does divine scripture, as being really divine, relate these things, even as the whole of our treatise goes to show. — The Christian Topography, Book 11 Jerome : (Verse 11.) The name of one is Phison. They believe this to be the river Ganges in India. (Verse 12.) Where (or There) is the carbuncle and the green stone. Some have translated carbuncle as βδέλλιον and the green stone as ὄνυχα. — Hebrew Questions on Genesis