Joshua 13:16
And their coast was from Aroer, that is on the bank of the river Arnon, and the city that is in the midst of the river, and all the plain by Medeba;
Cross-reference
Joshua 13:9 provides the identical geographic description of this territory, reinforcing the boundaries.
Joshua 12:2 describes Sihon's kingdom which included this same region, showing the conquered origin of the land.
Numbers 21:28-30 poetically recounts the conquest of Heshbon and Dibon, the very cities in this territory.
Numbers 32:33-38 records the original gift of this land to Reuben and Gad, paralleling the detailed inheritance.
Deuteronomy 3:12 gives the same territorial allotment to Reuben—from Aroer to the Arnon valley—confirming the inheritance boundaries.
2 Samuel 24:5 places Aroer on the valley of Gad, the same Aroer as Joshua 13:16—confirming its location in the Transjordan.
Isaiah 15:2 laments over Medeba, the very city named in Joshua 13:16 as part of Reuben's plain, now under Moabite judgment.
Isaiah 16:2 refers to the fords of Arnon, the same valley that marks the border in Joshua 13:16, linking the geography.
Isaiah 17:2 names the cities of Aroer, the same locality given to Reuben in Joshua 13:16, now destined for desolation.