With verses 10-14 the creative acts of God are interrupted to fill in more details of the description of Eden, and in particular to give the names of the rivers that water the garden. There are two ways to regard these verses: (1) as an attempt to give real geographical detail to Eden and the garden by using such names as Cush, Tigris, and Euphrates, and (2) not as describing the geography of Eden and the garden, but asserting that the fertility of every place has its origin in the rivers that watered Eden and its garden.

A river flowed out of Eden: flowed out means “rose, had its source, had its headwaters”; that is, “A river began to flow from Eden” or “A river had its headwaters in Eden.” This is the main river and is not named. To water the garden means “to irrigate the garden” or “to water the trees and plants in the garden.”

And there it divided and became four rivers: there can mean that the division took place in Eden before reaching the garden, or that there were four tributaries in Eden that flowed into the main stream, or that the main river divided into four streams somewhere in the garden, or, as nearly all modern translations interpret it, that the main river flowed through the garden and upon leaving the garden divided into four streams. This last view is the one recommended to translators. Four rivers is literally “four heads,” which refers to the parting points where the smaller streams separate from the main river.

Languages differ considerably in the use of terms for river, depending on whether they flow to the sea, empty into another river, or into a lake. Also distinguished sometimes are rivers that flow year round and those that flow only during the rainy season. Furthermore, some languages distinguish between the main river and its tributaries or branches. The picture in verse 10 is the separation of four streams from the main river.

Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .