Charles Ellicott Commentary Genesis 2:13

"And the name of the second river is Gihon: the same is it that compasseth the whole land of Cush." — Genesis 2:13 (ASV)

Gihon, “the river that bursts forth,” has been supposed to be the Nile, because it is said to wind about Ethiopia (Cush). According to this view, there was originally no break between Asia and Africa, and the Nile, entering Abyssinia from Arabia, took from there a northerly course, and traversed Egypt.

But Cush is now known to have signified at this period the southern half of Arabia, and it was not until later times that the name was carried by colonists to Abyssinia. Moreover, Gihon, in Arabic Jaihan, is a common name among the Arabs for a river, and perhaps the Oxus is here meant, which flowed northward from Armenia into the Caspian.

Mr. Sayce, however, thinks it is the Araxes, “the river of Babylon,” which flowed westward into the desert of Cush, in Arabia (Chald, Gen., p. 84).