Genesis 2:10

Pliny indeed relates, in his Sixth Book, that the Euphrates was so stopped in its course by the Orcheni, that it could not flow into the sea, except through the Tigris. And Pomponius Mela, in his Third Book, denies that it flowed by any given outlet, as other rivers, but says that it failed in its course. Nearchus, however, (whom Alexander had made commander of his fleet, and who, under his sanction, had navigated all these regions,) reckons the distance from the mouth of the Euphrates to Babylon, three thousand three hundred stadia. But he places the mouths of the Tigris at the entrance of Susiana; in which region, returning from that long and memorable voyage, he met the king with his fleet, as Adrian relates in his Eighth Book of the Exploits of Alexander. This statement Strabo also confirms by his testimony in his Fifteenth Book. Nevertheless, wherever the Euphrates either submerges or mingles its stream, it is certain, that it and the Tigris, below the point of their confluence, are again divided. Adrian, however, in his Seventh Book, writes that not one channel only of the Euphrates runs into the Tigris, but also many rivers and ditches, because waters naturally descend from higher to lower ground. With respect to the confluence, which I have noted in the plate, the opinion of some was, that it had been effected be the labor of the Praefect Cobaris, lest the Euphrates, by its precipitate course, should injure Babylon. But he speaks of it as of a doubtful matter. It is more credible, that men, by art and industry, followed the guidance of Nature in forming ditches, when they saw the Euphrates any where flowing of its own accord from the higher ground into the Tigris. Moreover, if confidence is placed in Pomponius Mela, Semiramis conducted the Tigris and Euphrates into Mesopotamia, which was previously dry; a thing by no means credible. There is more truth in the statement of Strabo, — a diligent and attentive writer, — in his Eleventh Book, that at Babylon these two rivers unite: and then, that each is carried separately, in its own bed, into the Red Sea. He understands that junction to have taken place above Babylon, not far from the town Massica, as we read in the Fifth Book of Pliny. Thence one river flows through Babylon, the other glides by Seleucia, two of the most celebrated and opulent cities. If we admit this confluence, by which the Euphrates was mixed with the Tigris, to have been natural, and to have existed from the beginning, all absurdity is removed. If there is anywhere under heaven a region preeminent in beauty, in the abundance of all kinds of fruit, in fertility, in delicacies, and in other gifts, that is the region which writers most celebrate. Wherefore, the eulogies with which Moses commends Paradise are such as properly belong to a tract of this description. And that the region of Eden was situated in those parts is probable from Isaiah 37:12 Ezekiel 27:23. Moreover, when Moses declares that a river went forth, I understand him as speaking of the flowing of the stream; as if he had said, that Adam dwelt on the bank of the river, or in that land which was watered on both sides if you choose to take Paradise for both banks of the river. However, it makes no great difference whether Adam dwelt below the confluent stream towards Babylon and Seleucia, or in the higher part; it is enough that he occupied a well-watered country. How the river was divided into four heads is not difficult to understand. For there are two rivers which flow together into one, and then separate in different directions; thus, it is one at the point of confluence, but there are two heads in its upper channels, and two towards the sea; afterwards, they again begin to be more widely separated.

The question remains concerning the names Pison and Gihon. For it does not seem consonant with reason, to assign a double name to each of the rivers. But it is nothing new for rivers to change their names in their course, especially where there is any special mark of distinction. The Tigris itself (by the authority of Pliny) is called Diglito near its source; but after it has formed many channels, and again coalesces, it takes the name of Pasitigris. There is, therefore, no absurdity in saying, that after its confluence it had different names. Further there is some such affinity between Pasin and Pison, as to render it not improbable, that the name Pasitigris is a vestige of the ancient appellation. In the Fifth Book of Quintus Curtius, concerning the Exploits of Alexander, where mention is made of Pasitigris, some copies read, that it was called by the inhabitants Pasin. Nor do the other circumstances, by which Moses describes three of these rivers, in accord with this supposition. Pison surrounds the land of Havila, where gold is produced. Surrounding is rightly attributed to the Tigris, on account of its winding course below Mesopotamia. The land of Havila, in my judgment, is here taken for a region adjoining Persia. For subsequently, in the twenty-fifth chapter (Genesis 25:1,) Moses relates, that the Ishmaelites dwelt from Havila unto Shur, which is contiguous to Egypt, and through which the road lies into Assyria. Havila, as one boundary, is opposed to Shur as another, and this boundary Moses places near Egypt, on the side which lies towards Assyria. Whence it follows, that Havila (the other boundary) extends towards Susia and Persia. For it is necessary that it should lie below Assyria towards the Persian Sea; besides, it is placed at a great distance from Egypt; because Moses enumerates many nations which dwelt between these boundaries. Then it appears that the Nabathaeans, of whom mention is there made, were neighbors to the Persian. Every thing which Moses asserts respecting gold and precious stones is most applicable to this district.

The river Gihon still remains to be noticed, which, as Moses declares, waters the land of Chus. All interpreters translate this word Ethiopia; but the country of the Midianites, and the conterminous country of Arabia, are included under the same name by Moses; for which reason, his wife is elsewhere called an Ethiopian woman. Moreover, since the lower course of the Euphrates tends toward that region, I do not see why it should be deemed absurd, that it there receives the name of Gihon. And thus the simple meaning of Moses is, that the garden of which Adam was the possessor was well watered, the channel of a river passing that way, which was afterwards divided into four heads.