ARNON. - Eastern tributary (today Wädi el-Mö-gib) of the Mar Morto, the largest after the Giordano.
It is formed by the confluence of the Seil es-Sufçi with the Wädi el-Mu'hres; near its mouth it receives on the right the tributaries Seil Heidän and Seil en-Nimr. It flows through a picturesque gorge in the reddish rock, reaching a depth of 650 m. Its waters abound in fish.
The A. marked the boundary Amorites (v.) with Hesebon as its capital, Ammonites (v.), to the north, and that of the Moabites, to the south (Num. 21, 13-15;
22, 36; iscrizione di Meïa, line 26); later it constituted the southern boundary of the tribe of Ruben (Jos. 13, 9, 16), that is, of the trans-Jordanian Israelite territory (Deut. 3, 12; 4, 48).
BIBL.: F.-M. Abel, Géographie de la Palestine, I, Parigi 1933, pp. 177 ff., 487 ff.; id., Une craintree autour de la Mer Morte, Parigi 1911, pp. 46-52. Gaetano M. Perrella