Genesis 2:10

The precise locality of Eden is indicated by its relation to the great watercourses of the region. And a river (literally, a flowing water, applicable to large oceanic floods— Job 22:16 ; Psalms 24:2 ; Psalms 46:5 ; Jonah 2:4 —as well as to narrow streams) went out (literally, going out) of Eden to water the garden. To conclude from this that the river had its source within the limits of the garden is to infer more than the premises will warrant. Nothing more is implied in the language than that a great watercourse proceeded through the district of Eden, and served to irrigate the soil. Probably it intersected the garden, thus occasioning its remarkable fecundity and beauty. And from thence ( i.e. either on emerging from which, or, taking מן in its secondary sense, outside of, or at a distance from which) it was parted (literally, divided itself), and became into four heads. Roshim , from rosh , that which is highest; either principal waters, arms or branches (Taylor Lewis, Alford), or beginnings of rivers, indicating the sources of the streams (Gesenius, Keil, Macdonald, Murphy). If the second of these interpretations be adopted, Eden must be looked for in a spot where some great flowing water is subdivided into four separate streams; if the former be regarded as the proper exegesis, then any great river which is first formed by the junction of two streams, and afterwards disperses its waters in two different directions, will meet the requirements of the case.