While Israel dwelt in Heshbon. — See Numbers 21:25. This is an argument from undisputed possession.
In Aroer and her towns. — These had been assigned to the tribe of Gad (Numbers 32:34).
In all the cities that be along by the coast of Arnon. — The LXX. read Jordan.
Three hundred years. — There is an almost insuperable difficulty in making out any reasonable scheme of chronology even by accepting this as a round number, because it is difficult to reconcile with nine or ten genealogies which have been preserved to us, and which represent the period between the conquest and David by seven or eight generations. Now the period covered by these genealogies includes the judgeship of Samuel and the reign of Saul — at least seventy years; and seven or eight generations cannot possibly span 370 years. The hypothesis that in all these genealogies — even the four times repeated genealogy of David — generations are always omitted is very improbable. The chronology of the Jews is confessedly loose and uncertain, and it seems quite possible that “three hundred years” may be a marginal gloss which has crept into the text. What makes this more probable is that the words not only create an immense chronological difficulty, but (1) are quite needless to Jephthah’s argument, and (2) actually conflict with the rest of the sentence, which refers to Balak alone; the argument being, If Balak, “at that time” (as the words should be rendered), did not advance any claim, what right have you to do so now? If, however, in spite of these difficulties, the clause be genuine, and if there has not been one of the clerical errors which are so common where numerals are concerned, it seems possible that 300 years may be counted inclusively, e.g., 100 full years since the death of Joshua and nominal completion of the conquest of Canaan, with parts of a century before and after it. Certainly this is a recognised mode of reckoning time among the Jews. For instance, if a king began to reign on December 30, 1879, and died on January 2, 1881, they would say that he had reigned three years. Whatever explanations we may adopt, there is nothing but conjecture to go upon. (See Introduction.)
Within that time. — This is a mistranslation, due probably to the perplexity caused by the “three hundred years.” The Hebrew has “in that time,” i.e., at that crisis. It was obvious, without special mention, that they had remained in possession ever since Balak’s day, and in the most ancient times it was admitted that lapse of time secured possession (Isocr. Ep. ad Aechid., p. 121; Tac. Ann. vi. 31).