‘ And the men arose and went, and Joshua charged those who went to describe the land, saying, “Go and walk through the land and describe it in writing, and come again to me, and I will cast lots for you here before YHWH in Shiloh.” '
So Joshua gave his last instructions to the men in accordance with what he had told the princes (Joshua 18:4). The repetition enabled the listener to remind himself of what had been said and to be able to say it along with the narrator. It encouraged participation. The surveyors were to go through the land (whether together as a caravan, or separately in small groups is not said) and record in writing all the information needed for a fair division of the land. Then the information would be used to cast lots before YHWH at Shiloh, where they then were, in order to discover His will.