1. Exposition

Where is the record of the LORD's instructing Moses on how to divide the land?

Joshua 11:23 (ESV)

23 So Joshua took the whole land, according to all that the LORD had spoken to Moses. And Joshua gave it for an inheritance to Israel according to their tribal allotments. And the land had rest from war.

The principle that was to guide the division was given by the Lord to Moses in Numbers 26:52–56.