יהושע, פרק א׳, פסוק ט״ו

The settling of a new homeland requires shared sacrifice and national unity. For the tribes claiming territory on the eastern side of the Jordan River, specifically the side where the sun rises [רש"י, מצודת דוד, ביאור שטיינזלץ], their right to the land is not absolute until a broader national mission is fulfilled. These tribes are bound by a strict pact of mutual solidarity. They cannot return to their lands to build their private lives until they ensure that the rest of the nation achieves peace and secures their own territory across the river. They are required to wait and actively participate in the military campaign until God grants the remaining tribes a place of rest, mirroring the peace they themselves currently enjoy [מצודת דוד, ביאור שטיינזלץ].

This period of shared struggle must continue until the conquest and division of the land are entirely finished, ensuring every tribe receives its rightful inheritance [מלבי"ם]. The very right to the territory granted to them by Moses is strictly conditional on keeping this promise; the land was given to them only on the condition that they do not abandon their brothers in battle [מלבי"ם]. Only after they fully honor this commitment will their own inheritance become permanent. Once the condition is met, they will be able to put down deep roots, take lasting hold of their territory, and rule over it without any challenge [מצודת דוד, ביאור שטיינזלץ].