Hebrew, Perath; Assyrian, Purat; Persian cuneiform, Ufratush, whence Greek Euphrates, meaning "sweet water." The Assyrian name means "the stream," or "the great stream." It is generally called in the Bible simply "the river" (Ex. 23:31), or "the great river" (Deut. 1:7). The Euphrates is first mentioned in Gen. 2:14 as one of the rivers of Paradise. It is next mentioned in connection with the covenant which God entered into with Abraham (15:18), when he promised to his descendants the land from the river of Egypt to the river Euphrates (comp. Deut. 11:24; Josh. 1:4), a covenant promise afterwards fulfilled in the extended conquests of David (2 Sam. 8:2-14; 1 Chr. 18:3; 1 Kings 4:24). It was then the boundary of the kingdom to the north-east. In the ancient history of Assyria, and Babylon, and Egypt many events are recorded in which mention is made of the "great river." Just as the Nile represented in prophecy the power of Egypt, so the Euphrates represented the Assyrian power (Isa. 8:7; Jer. 2:18). It is by far the largest and most important of all the rivers of Western Asia. From its source in the Armenian mountains to the Persian Gulf, into which it empties itself, it has a course of about 1,700 miles. It has two sources, (1) the Frat or Kara-su (i.e., "the black river"), which rises 25 miles north-east of Erzeroum; and (2) the Muradchai (i.e., "the river of desire"), which rises near Ararat, on the northern slope of Ala-tagh. At Kebban Maden, 400 miles from the source of the former, and 270 from that of the latter, they meet and form the majestic stream, which is at length joined by the Tigris at Koornah, after which it is called Shat-el-Arab, which runs in a deep and broad stream for above 140 miles to the sea. It is estimated that the alluvium brought down by these rivers encroaches on the sea at the rate of about one mile in thirty years. that makes fruitful is probably a word of Aryan origin, signifying "the good and abounding river. " It is most frequently denoted in the Bible by the term "the river." The Euphrates is the largest, the longest and by far the most important of the rivers of western Asia. It rises from two chief sources in the Armenian mountains, and flows into the Persian Gulf. The entire course is 1780 miles, and of this distance more than two-thirds (1200 miles) is navigable for boats. The width of the river is greatest at the distance of 700 or 800 miles from its mouth--that is to say, from it junction with the Khabour to the village of Werai . It there averages 400 yards. The annual inundation of the Euphrates is caused by the melting of the snows in the Armenian highlands. It occurs in the month of May. The great hydraulic works ascribed to Nebuchadnezzar had for their chief object to control the inundation. The Euphrates is first mentioned in Scripture as one of the four rivers of Eden. (Genesis 2:14) We next hear of it in the covenant made with Abraham. (Genesis 15:18) During the reigns of David and Solomon it formed the boundary of the promised land to the northeast. (11:24; Joshua 1:4) Prophetical reference to the Euphrates is found in (Jeremiah 13:4-7; 46:2-10; 51:63; Revelation 9:14; 16:12) "The Euphrates is linked with the most important events in ancient history. On its banks stood the city of Babylon; the army of Necho was defeated on its banks by Nebuchadnezzar; Cyrus the Younger and Crassus perished after crossing it; Alexander crossed it, and Trajan and Severus descended it."--Appleton's Cyc.
Euphrates