John Calvin Commentary Joshua 16

And the lot of the children of Joseph fell, etc. The sacred writer first states what the lot was that fell to the two children of Joseph, and then describes the lot of Ephraim. It is strange, however, that when half of the tribe of Manasseh had already been settled beyond the Jordan, more words are used in describing the remaining half than in describing the whole inheritance of the tribe of Ephraim, even though the latter was more populous and justly claimed a larger territory for itself.

But the longer detail given concerning the posterity of Manasseh is due to particular circumstances:

1. The writer repeats how a settlement had been given to them without lot in the country of Bashan.
2. He mentions Joshua's ratification of the command that Moses had given by divine authority regarding the daughters of Zelophehad.

Therefore, since there was no doubt regarding the boundaries of Ephraim, and there was no danger of dispute, their allocation is only briefly mentioned.

But here a new question arises. When the right of primogeniture had passed from Manasseh to Ephraim, how did the posterity of that tribe, which had precedence in rank, obtain their cities among the children of Manasseh? For their condition seems in this way to have been inferior. My explanation is this: when Manasseh's portion was too extensive in proportion to the size of its population, a calculation was made, and certain cities were deducted to complete the just share of the tribe of Ephraim; they were not mixed up with the children of Manasseh, to hold their dwellings among them by a precarious tenure, but instead their boundaries were merely extended in the direction of the Manassites, for whom a narrower possession would suffice.

At the end of the chapter, Ephraim is severely censured for his culpable weakness in not having expelled the Canaanites from Gezer. For if they had proceeded in a resolute and wholehearted manner to secure their right to the land that had fallen to them by lot, the victory was in their hands. There would have been no temerity in the attempt, since the decision of the lot was as valid as if the Lord Himself had stretched out His hand from heaven.

But their disgraceful sloth is more clearly expressed, and their culpability is greatly heightened by the fact that they made tributaries of those with whom it was not lawful to enter into any kind of arrangement. Therefore, since God had distinctly forbidden His people to transact business of any kind with those nations, and least of all to enter into pacts with them stipulating their pardon and safety, the Ephraimites sinned much more grievously by exacting tribute than if they had tolerated them without a pact.