EASTON’S BIBLE DICTIONARY (1897 EDITION)
Arnon – swift, the southern boundary of the territory of Israel beyond Jordan, separating it from the land of Moab (Deut. 3:8, 16).
This river (referred to twenty-four times in the Bible) rises in the mountains of Gilead, and after a circuitous course of about 80 miles through a deep ravine it falls into the Dead Sea nearly opposite Engedi.
The stream is almost dry in summer.
It is now called el-Mujeb.
The territory of the Amorites extended from the Arnon to the Jabbok.