Matthew Poole and continuators on Genesis 2:10

10. And a River went out of Eden to water the Garden, and from thence it was parted, and became into four heads .

Or, Rivers, by a common Enallage.

The Country in which Paradise was; where those Rivers either arose from one spring, or met together in one channel.

(i. e.) From the Garden.

It was divided into four principal Rivers. Concerning which there are now many disputes. But it is no wonder if the rise and scituation of these Rivers be not now certainly known, because of the great changes, which in so long time might happen in this, as well as in other Rivers, partly by Earth-quakes, and principally by the general Deluge. And yet Euphrates and Tigris, the chief of these Rivers, whereof the other two are branches, are discovered by some learned men, to have one and the same original or spring, and that in a most pleasant part of Armenia, where they conceive Paradise was. See my Latin Synopsis.