On yonder side Jordan. מֵעֵבֶר לירְדֵּן. Septuagint, ἀπὸ τοῦ πέραν τοῦ ἰορδάνου. This phrase is here used in what is apparently its more natural sense, as it would be used by one dwelling in the plains of Moab (see on Numbers 22:1, and on next verse).
Or forward. וָהָלְאָה. Septuagint, καὶ ἐπέκεινα, i.e; onwards towards the west and south and north, as the tide of conquest might flow. Our inheritance is fallen to us on this side Jordan eastward.
It does not appear on what ground they spoke so confidently. They do not seem to have received any Divine intimation that their lot was to be on the east of Jordan, but rather to have been guided by their own preference.
If so, they cannot be acquitted of a certain presumptuous willfulness in action, and of a certain want of honesty in speech. The phrase here rendered "on this side Jordan" ( מֵעֵבֶר היּרְדֵּז) cannot be distinguished grammatically from that which bears an opposite signification in the preceding verse.
In itself it is perfectly ambiguous without some qualifying word or phrase, and it is very difficult to know what the ordinary use of it was in the time of Moses. In later ages, no doubt, it came to mean simply the trans-Jordanic territory, or Peraea, without reference to the position of the speaker.
The difficulty here is to decide whether the expression, as further defined by "eastward," would actually have been used at that time and in that place, or whether the expression is due to a writer living on the west of Jordan.
All we can say is, that the awkward use of the phrase in two opposite meanings, with words of clearer definition added, points more or less strongly towards a probability that the passage as it stands was written or revised at a later date.