John Wesley on Joshua 17:15

A great people - He retorts their own argument; seeing thou art a great and numerous people, turn thy complaints into action, and enlarge thy borders by thy own hand, to which thou mayest confidently expect God's assistance. The wood - country - To the mountain, as it is called, ver.18, where among some towns there is much wood - land, which thou mayest without much difficulty possess, and so get the more room. And cut down - The wood, for thy own advantage; in building more cities and towns; and preparing the land for pasture and tillage. The Perizzites - Supposed to be a savage and brutish kind of people, that lived in woods and mountains. Giants - Who lived in caves and mountains, now especially when they were driven out of their cities. If mount Ephraim - Or, seeing mount Ephraim is too narrow for thee, as thou complainest; take to thyself the rest of that hilly and wood country. Mount Ephraim was a particular portion of the land, belonging to the tribe of Ephraim. And this seems to be here mentioned, for all the portion allotted to Ephraim and Manasseh, as appears from their complaint, which was not, that this part, but that their whole portion was too strait for them.