Thou shalt not have one lot only - i. e. by dispossessing the Canaanites, thou shalt double the portion of land at thy disposal. The "but" with which the King James Version begins Joshua 17:18 should be "for."

And Joshua spake unto the house of Joseph, even to Ephraim and to Manasseh,.... From whence it is clear that some of both were present; and they being brethren, and their interests united, and their cities intermixed, it would be to their mutual advantage to have an enlargement; which the tribe of Manasseh wanted more especially, more of their cities that fell to their lot being in the hands of the Canaanites, than of any other:

saying, thou art a great people, and hast great power; were very numerous, and so able to contend with the Canaanites, and make themselves more room:

thou shalt not have one lot only; or only have what they were possessed of, but should have more; and, as they wanted more, they were able enough to get more; and if they exerted their power, relying on the providence of God, through his blessing on their endeavours, they would certainly have an increase of their portion.

As the answer of the children of Joseph indicated cowardice and want of confidence in the help of God, Joshua contented himself with repeating his first reply, though more fully and with the reasons assigned. "Thou art a strong people, and hast great power; there will not be one lot to thee:" i.e., because thou art a numerous people and endowed with strength, there shall not remain one lot to thee, thou canst and wilt extend thine inheritance. "For the mountain will be thine, for it is forest, and thou wilt hew it out, and its goings out will become thine." By the mountain we are not to understand the mountains of Ephraim which were assigned to the Ephraimites by the lot, but the wooded mountains mentioned in Joshua 17:15, which the children of Joseph were to hew out, so as to make outlets for themselves. "The outgoings of it" are the fields and plains bordering upon the forest. For the Canaanites who dwelt there (Joshua 17:15) would be driven out by the house of Joseph, just because they had iron chariots and were strong, and therefore only a strong tribe like Joseph was equal to the task. "Not one of the tribes of Israel is able to fight against them (the Canaanites) because they are strong, but you have strength enough to be able to expel them" (Rashi).

And Joshua spake unto the house of Joseph, even to Ephraim and to Manasseh, saying, Thou art a great people, and hast great power: thou shalt not have one lot only:

17:17 One lot only - Thou needest and deservedst more than that lot, of which thou art actually possessed, and thou hast power to get more; which if thou endeavourest to do, God will bless thee, and give thee more.

17:14-18 Joshua, as a public person, had no more regard to his own tribe than to any other, but would govern without favour or affection; wherein he has left a good example to all in public trusts. Joshua tells them, that what was fallen to their share would be a sufficient lot for them, if they would but work and fight. Men excuse themselves from labour by any pretence; and nothing serves the purpose better than having rich and powerful relations, able to provide for them; and they are apt to desire a partial and unfaithful disposal of what is intrusted to those they think able to give such help. But there is more real kindness in pointing out the advantages within reach, and in encouraging men to make the best of them, than in granting indulgences to sloth and extravagance. True religion gives no countenance to these evils. The rule is, They shall not eat who will not work; and many of our cannots are only the language of idleness, which magnifies every difficulty and danger. This is especially the case in our spiritual work and warfare. Without Christ we can do nothing, but we are apt to sit still and attempt nothing. if we belong to Him, he will stir us up to our best endeavours, and to cry to him for help. Then our coast will be enlarged, 1Ch 4:9,10, and complainings silenced, or rather, turned into joyful thanksgivings.