Give out from among you three men for each tribe: and I will send them, and they shall rise, and go through the land, and describe it according to the inheritance of them; and they shall come again to me. Three men for each tribe - Probably meaning only three from each of the seven tribes who had not yet received their inheritance. It is likely that these twenty-one men were accompanied by a military guard, for without this they might have been easily cut off by straggling parties of the Canaanites.
They shall - describe it - It is likely they were persons well acquainted with geography and mensuration, without which it would have been impossible for them to have divided the land in the way necessary on this occasion.