When ephraim and manasseh complained they needed more land what did what did Joshua tell them?

After Joshua had allotted portions of the newly-conquered land of Canaan to each of the tribes of Israel, the people of Ephraim and Manasseh complained that Joshua had given them only one lot although they were a great and numerous people. In response, Joshua invited them to go up to the forest country and conquer more land by wresting it from the Perizzites and giants who inhabited it. Ephraim and Manasseh worried that they would not be able to conquer these Canaanite peoples, who had iron chariots; but Joshua insisted that they would succeed in driving out the Canaanites. By occupying the mountain country, they would obtain a sufficient plot of land.

The incident is recorded in the Biblical book of Joshua, chapter 17, verses 14 to 18.