EUPHRATES , one of the rivers of Eden ( Genesis 2:14 ), derives its name from the Assyr. [Note: Assyrian.] Purat , which is itself taken from the Sumerian Pura , ‘water,’ or Pura-nun , ‘the great water.’ Purat became Ufrâtu in Persian, where the prosthetic vowel was supposed by the Greeks to be the word u , ‘good.’ In the OT the Euphrates is generally known as ‘ the river .’ It rises in the Armenian mountains from two sources, the northern branch being called the Frat or Kara-su, and the southern and larger branch the Murad-su (the Arsanias of ancient geography). The present length of the river is 1780 miles, but in ancient times it fell into the sea many miles to the north of its existing outlet, and through a separate mouth from that of the Tigris. The salt marshes through which it passed before entering the sea were called Marratu ( Merathaim in Jeremiah 50:21 ), where the Aramæan Kalda or Chaldæans lived. The alluvial plain between the Euphrates and the Tigris constituted Babylonia, the water of the annual inundation (which took place in May, and was caused by the melting of the snows in Armenia) being regulated by means of canals and barrages. The Hittite city of Carchemish stood at the point where the Euphrates touched Northern Syria, and commanded one of the chief fords over the river; south of it came the Belikh and Khabur, the last affluents of the Euphrates. The promise made to the Israelites that their territory should extend to ‘the great river’ ( Genesis 15:18 etc.) was fulfilled through the conquests of David ( 2Sa 8:3; 2 Samuel 10:16-19 , 1 Kings 4:24 ).

A. H. Sayce.