'Forest' in the Bible

So Joshua replied to them, "Since you're so numerous, go up to the forest and clear ground there for yourselves in the territory where the Perizzites and Rephaim are, because the hill country of Ephraim is too narrow for you."

but the hill country will also belong to you. Even though it's a forest, you will clear it and possess it to its farthest borders. You'll drive out the Canaanites, even though they have iron chariots and even though they're strong."