And the name of the second river is Gihon: the same is it that compasseth the whole land of Ethiopia.
Gihon (bursting forth). The name denotes a rapid river issuing impetuously from its fountains.
Compasseth the whole land of Ethiopia, [Hebrew, the land of Cush]. There is more than one country indicated by this name in Scripture, which, signifying 'black,' and applied to people of sable or dusky complexion, is commonly considered as including Egypt and African Ethiopia. Hence, many who are of opinion that Eden embraced a very extensive territory, as the language of the sacred narrative evidently implies, place Gihon in the Nile, which takes the course indicated in this passage. But since the sons of Cush seem to have, by various successive migrations (cf. Genesis 10:1-32) wandered into regions widely removed from each other, the Hebrews used the term 'land of Cush' in a very loose and general sense, as descriptive of all the countries lying along the southern coast of Asia, from the Persian Gulf westward to the eastern coast of Africa; and it is now established that, according to Scripture usage, there is an Arabian as well as an African Ethiopia.
Hiddekel - the Tigris. The first syllable of this word being not an essential part of it, is supposed by Tuch to be the Hebrew adjective sharp, so that the name signifies the 'swift dekel,' or, as it is in the Aramoean forms, Digla and Deklath, Diglad in Josephus Diglito in Pliny, and now Dijel by the natives of Mesopotamia. The same meaning substantially is given by Sir H. Rawlinson ('Journal of the Royal Asiatic Society'), who derives it, however, from a different etymology, and apparently in a more satisfactory manner. According to him, Dekel, supposed to denote in the old Babylonian language 'an arrow,' becomes through the common interchange of the liquid semi-consonants "l" or "r", the tiggar (arrow) of the cuneiform inscriptions, and thence the Tigris of the Greeks; so that Hiddekel, with the prefix, through all these mutations of form, signifies 'the arrow' - i:e., the darting, impetuous river. It makes a great bend in its course toward the east at Diarbekr, and hence, is aptly described in the text as "it which goeth eastward toward Assyria," (margin).
Euphrates. This river being well known to the Hebrews is simply mentioned, without the addition of any topographical circumstances to indicate its course. The Hebrew name х Pªraat (H6578)] was long supposed to have been the original one, changed by the Greeks into the more euphonious form of Euphrates, and to have been derived from the Hebrew word for fruit, abundance, so that the name meant the 'fruitful,' the 'fertilizing' river.
Recent investigations, however, have shown the incorrectness of this opinion; because the name as we have it is, with a slight change of termination, identically the same as that applied to it by the ancient Babylonians. Rawlinson has discovered it in the Behistun cuneiform inscriptions as Ufrata, which is a compound of "u", (Greek, eu (G2095)) or "su", "very", and the adjective frata, "broad". The true import of the word Euphrates, therefore, is 'very broad;' and this name, as given in the sacred text, seems also to be accordant with the recently deciphered relics of Assyria; [for it stands thus: "the fourth river is huw' (H1931) Pªraat (H6578)." The first word, that or the, is omitted by our translators, who appear not to have considered it of any importance. But supposing, as has been ingeniously conjectured (Journal of Sacred Literature, July, 1864), that hu was an early form of the article, we find in hufrath that the ancient name has been exactly preserved in the narrative of Moses].