The allocation of the land of Israel involved precise measurements, but the tribe of Manasseh experienced a unique family and territorial situation that resulted in their land being divided into ten distinct regions west of the Jordan River. In ancient times, land was measured and distributed using a physical measuring rope to define these specific districts [ביאור שטיינזלץ, מצודת ציון]. These ten separate areas within the land of Israel were granted to the tribe in addition to the territories they already possessed in Gilead and Bashan, east of the Jordan [מצודת דוד, ביאור שטיינזלץ].
The allocation of ten distinct portions presents a mathematical puzzle, as the half of the tribe settling on the western side consisted of only six families. Commentators offer two primary ways to understand this division, blending family inheritance laws with geographical realities.
The primary approach, rooted in the teachings of the Sages, explains the division through the lens of lineage and inheritance. The six main families received six portions, while the remaining four were awarded to the daughters of Zelophehad. These women received four shares because they inherited their father's regular portion, his share in the estate of their grandfather Hepher, a double portion due to their father's status as a firstborn, and the territory of an uncle who died in the desert without sons [רש״י, רד״ק]. This calculation is based on the principle that the distribution of the land was determined by the census of the generation that left Egypt [רד״ק, אברבנאל].
This specific distribution highlights an important legal foundation regarding the land. According to Jewish law, a firstborn can only claim a double portion of assets that are already physically held, not prospective or future assets. The fact that the daughters of Zelophehad could claim a firstborn's double portion demonstrates that the land of Israel was legally considered property already held and possessed since the days of the forefathers [רש״י].
In contrast to this family-based legal calculation, a more straightforward geographical approach suggests that the ten portions simply represent ten physical districts rather than family inheritance quotas. These districts consisted of major cities and their surrounding towns, such as Beit She'an, Megiddo, and Dor, each forming a distinct, carefully measured unit of land [מלבי״ם]. Ultimately, these two perspectives provide a complete picture of the inheritance, with one highlighting the historical and legal rights of the families, and the other mapping out the actual territorial layout of their new home.