Deuteronomy 2:19

when thou comest nigh over against the children of Ammon And thou shalt approach to the front of the Bnê -Ammôn. The expression is vague and the mention of -Ammôn at this stage perplexing. It is true that, acc. to Judges 11:13, the -Ammonites declared to Jephthah that Israel coming out of Egypt took away their land from Arnon even unto Jabboḳ. But the passage to which this belongs, Judges 11:12-28, generally regarded as late and confused, repels the -Ammonite claim and affirms (Deuteronomy 2:22) that the land between Arnon and Jabboḳ had been held by the Amorites. This, too, is the testimony of the oldest traditions JE, Numbers 21:13; Numbers 21:24; Numbers 21:31 f., which also relate that the Amorites had taken that territory not from -Ammôn, but from Mo'ab (id.Numbers 21:26-30); cp. the evidence both of JE and P in Numbers 22 ff., that the land N. of Arnon was Moabite. The evidence thus preponderates that -Ammôn was confined to a small territory on the upper Jabboḳ, where Rabbath--Ammôn (chief town of -A.) was situated (though before the -Amorite invasion of E. Palestine they may have held the whole course of Jabboḳ immediately S. of that). On the Arnon, therefore, Israel was still some 35 miles from Ammonite territory and the Amorites lay between. The mention of -Ammôn at this stage thus appears proleptic, and coinciding as it does with a change to the Sg. address, may plausibly be maintained to be the insertion of a later writer, perhaps influenced by Judges 11:13. On the other hand it is just possible that the reference to -Ammôn at this stage was held by the author of the discourse himself to be necessary, as intended to divert Israel from the due northerly direction which they had been pursuing and which, if continued, would bring them into conflict with -Ammôn; and to turn them N.W. through the Amorites to the Jordan.