I recently spent some time studying Genesis 2:10-14, looking at all my commentaries from Origen, Theodoret, and Augustine all the way up through 21st century commentators. Almost every commentator spent his time discussing the possible location of Eden.
(In my opinion Luther [along with Leupold] was the most sensible of any; he argues Eden was obliterated by the Flood. This explanation didn’t seem to occur to ancient commentators, and modern commentators shy away from this explanation because it seems to support young-earth creationism–though it would seem even a flood confined to the region of the Middle East that did the half of what Genesis said it did would have destroyed Eden and reshaped the rivers. Calvin was a bit disappointing on this matter. He grants the global Flood, but he says that he doesn’t think it changed the earth and that in any event, Moses was locating Eden according to post-Flood geography.)
But aside from patristic and medieval allegorists, almost no one addressed the issue of why the passage is included in Genesis 2. Liberal scholars claim the passage doesn’t fit the chapter and was therefore a later addition to the J source. While this is nonsensical on one level, it does raise the issue of why Moses included the text. Only two of the commentators I consulted attempted at an answer.
Oecolampadius says: “There are some who try to bring in different allegories for these rivers. Some bring forth the four evangelists, others the four doctors of the church [Ambrose, Jerome, Augustine, and Gregory the Great]. Avoid such trifles. It is much safer just to know that God wished humankind well, and that he gave all the resources of this world in order that we might enjoy them to his glory.” Johannes Oecolampadius, In Genesim, 34r-v cited in John L. Thompson, ed., Genesis 1-11, Reformation Commentary on Scripture, ed. Timothy George (Downers Grove: InterVarsity, 2012), 86.
And Kidner says, “There is a hint of the cultural development intended for man when the narrative momentarily (10-14) breaks out of Eden to open up a vista into a world of diverse countries and resources. The digression, overstepping the bare details that locate the garden, discloses that there is more than primitive simplicity in store for the race: a complexity of unequally distributed skills and peoples, even if the reader knows the irony of it in the tragic connotations of the words ‘gold,’ ‘Assyria,’ ‘Euphrates.’” Derek Kidner, Genesis: An Introduction and Commentary, Tyndale Old Testament Commentary (Downers Grove: InterVarsity, 1982), 61.
Kidner’s explanation fits well in the overall context of the passage. This passage links the Creation Blessing of chapter 1 to the more specific task given to Adam of keeping and tending the garden (2:15). Alan Jacobs notes, “Gardening marks, as clearly as any activity, the joining of nature and culture. The gardener makes nothing, but rather gathers what God has made and shapes it into new and pleasing forms. The well-designed garden shows nature more clearly and beautifully than nature can show itself” (“Gardening and Governing,” Books and Culture [March/April 2009]: 18.) A garden is a plot of earth over which someone has exercised dominion. God starts man off in a garden. He is told to tend it, but the Creation Blessing reveals that he is to extend it as well. The geography lesson about the location and topography of Eden reveals that the building blocks of society are already close at hand. The four rivers are highways into the world. And these rivers lead to lands in which important natural resources can be found.